STLC7550 Low Power Low Voltage Analog Front End Features General purpose signal processing Analog Front End (AFE) Targeted for V.34bis Modem and 56Kbps Modem applications 16-BIT oversampling A/D and D/A converters 83dB signal to noise ratio for sampling frequency up to 9.6kHz @ 3V 87dB dynamic range @ 3V Filter bandwidths: 0.425 x the sampling frequency On-chip reference voltage Single power supply range: 2.7 to 5.5V Low power consumption less than 30mW operating power 3V Stand-by mode power consumption less than 3mW at 3V Programming sampling frequency Max. sampling frequency : 45kHz Synchronous serial interface for processor datas exchange Master or Slave operations 0.50m CMOS process TQFP48 package STLC7546 mode of operation compatible ) s ( t c u d o ) r s ( P t c e t u e d l o o r s P b e O t e l ) o s ( s t b c u O d o ) r s P ( t c e t u e l d Description o o r s P b O e t e l o Order s codes b O The STLC7550 is a single chip Analog Front-end (AFE) designed to implement modems up to 56Kbps. TQFP48 (7 x 7 x 1.4mm) (Full Plastic Quad Flat Pack) It has been especially designed for host processing application in which the modulation software (V.34bis, 56Kbps) is performed by the main application processor : Pentium, Risc or DSP processors. The main target of this device is stand alone appliances as Hand Held PC (HPC), Personnal Digital Assistants (PDA), Webphones, Network Computers, Set Top Boxes for Digital Television (Satellite and Cable). To comply with such applications STLC7550 is powered nominally at 3V only. Maximum Power Dissipation 30mW is well suited for Battery operations. In case of battery low, STLC7550 will continue to work even at a 2.7V level. STLC7550 also provides clock generator for all sampling frequencies requested for V.34bis and 56Kbps applications. This new AFE can also be used for PC mother boards or add-on cards or stand alone MODEMs. It can be used in a master mode or slave mode. The slave mode eases multi AFE architecture design in saving external logical glue. Part number Temp range, C Package Packing STLC7550TQF7 0 to 70 TQFP48 Tube STLC7550TQF7TR 0 to 70 TQFP48 Tape & Reel E-STLC7550TQF7 (*) 0 to 70 TQFP48 Tube (*) ECOPACK(R) (see Section 6) February 2006 Rev 9 1/24 www.st.com 24 Content STLC7550 Content 1 Pins description & Block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 1.1 2 Pin description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 1.1.1 Power Supply (5 pins) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 1.1.2 Host interface (10 pins) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 1.1.3 Clock signals (2 pins) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 1.1.4 Analog interface (9 pins) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 Functional description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 ) s ( t c u d o ) r s ( P t c e t u e d l o o r s P b e O t e l ) o s ( s t b c u O d o ) r s P ( t c e t u e l d o o r s P b O e t e l o s b O 2.1 2.2 3 Transmit D/A section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 2.1.1 Transmit Low Pass Filters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 2.1.2 D/A Converter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Receive A/D section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 2.2.1 A/D Converter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 2.2.2 Receive Low Pass Filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 2.3 Clock generator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 2.4 Modes of operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 2.5 Host interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 2.6 Control register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 Electrical Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 3.1 Absolute maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 3.2 Nominal DC Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 3.3 Nominal AC Electrical Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 3.4 Transmit Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 3.5 3.4.1 Performance of the Tx channel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 3.4.2 Smoothing filter transfer characteristics . . . . . . . . . . . . . . . . . . . . . . . . . 19 Receive Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 3.5.1 Performance of the Rx channel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 4 Typical application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 5 Definition and Terminology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 6 Package information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 7 Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 2/24 Rev 9 STLC7550 Pins description & Block diagram MCM DGND DVDD FS SCLK Pin connection (top view) XTALOUT Figure 1. XTALIN/MCLK 1 Pins description & Block diagram 12 11 10 9 8 7 6 5 4 3 2 1 13 48 14 47 ) s ( t c u d o ) r s ( P t c e t u e d l o o r s P b e O t e l ) o s ( s t b c u O d o ) r s P ( t c e t u e l d o o r s P b O e t e l o s b O HC1 15 46 HC0 16 45 DOUT PWRDWN 17 44 DIN M/S 18 43 TSTD1 VREFP 19 42 TS VREFN 20 41 RESET AGND1 21 40 OUT- 22 39 OUT+ 23 38 24 37 Table 1. AGND2 VCM AVDD IN- IN+ AUXIN- AUXIN+ 25 26 27 28 29 30 31 32 33 34 35 36 Pin list Pin # Pin Name Type Description 1 - 2, 10 to 14, 22 to 26, 34 to 38, 46 to 48 NC - Not connected 3 SCLK O Shift Clock Output 4 FS I/O Frame Synchronization Input (slave)/Output (master) 5 DVDD I Positive Digital Power Supply (2.7V TO 5.5V) 6 DGND I Digital Ground 7 MCM I Master Clock Mode 8 XTALOUT O Crystal Output 9 XTALIN/MCLK I Crystal Input (MCM = 1) / External Clock (MCM = 0) 15 HC1 I Hardware Control Input 16 HC0 I Hardware Control Input 17 PWRDWN I Power down Input 18 M/S I Master/Slave Mode Control Pin Input 19 VREFP O 16-bit D/A and A/D Positive Reference Voltage 20 VREFN O 16-bit D/A and A/D Negative Reference Voltage Rev 9 3/24 Pins description & Block diagram Table 1. STLC7550 Pin list (continued) Pin # Pin Name Type Description 21 AGND1 I Analog Ground 27 AUXIN+ I Non-inverting Input to Auxiliary Analog Input 28 AUXIN- I Inverting Input to Auxiliary Analog Input 29 IN+ I Non-inverting Input to Analog Input Amplifier 30 IN- I Inverting Input to Analog Input Amplifier 31 AVDD I Positive Analog Power Supply (2.7V to 5.5V) 32 VCM O Common Mode Voltage Output (AVDD/2) 33 AGND2 I Analog Ground 39 OUT+ O Non-inverting Smoothing Filter Output 40 OUT- O Inverting Smoothing Filter Output 41 RESET I Reset Function to initialize the internal counters 42 TS I Timeslot Control Input 43 TSTD1 I/O 44 DIN I Serial Data Input 45 DOUT O Serial Data Output ) s ( t c u d o ) r s ( P t c e t u e d l o o r s P b e O t e l ) o s ( s t b c u O d o ) r s 1.1 Pin description P ( t c e t u e l d o o r s P b O e t e l o s b O Note: 1.1.1 Digital Input/Output reserved for test 1 To obtain published performance, the analog VDD and Digital VDD should be decoupled with respect to Analog Ground and Digital Ground, respectively. The decoupling is intended to isolate digital noise from the analog section ; decoupling capacitors should be as close as possible to the respective analog and digital supply pins. 2 All the ground pins must be tied together. In the following section, the ground and supply pins are referred to as GND and VDD, respectively. Power Supply (5 pins) Analog VDD Supply (AVDD) This pin is the positive analog power supply voltage for the DAC and the ADC section. It is not internally connected to digital VDD supply (DVDD). In any case the voltage on this pin must be higher or equal to the voltage of the Digital power supply (DVDD). Digital VDD Supply (DVDD) This pin is the positive digital power supply for DAC and ADC digital internal circuitry. Analog Ground (AGND1, AGND2) These pins are the ground return of the analog DAC (ADC) section. 4/24 Rev 9 STLC7550 Pins description & Block diagram Digital Ground (DGND) This pin is the ground for DAC and ADC internal digital circuitry. 1.1.2 Host interface (10 pins) Data In (DIN) In Data Mode, the data word is the input of the DAC channel. In software, the data word is followed by the control register word. Data Out (DOUT) In Data Mode, the data word is the ADC conversion result. In software, the data word is followed by the register read. ) s ( t c u d o ) r s ( P t c e t u e d l o o r s P b e O t e l ) o s ( s t b c u O d o ) r s P ( t c e t u e l d o o r s P b O e t e l o s b O Frame Synchronization (FS) In master mode, the frame synchronization signal is used to indicate that the device is ready to send and receive data. The data transfer begins on the falling edge of the frame-sync signal. The framesync is generated internally and goes low on the rising edge of SCLK in master mode. In slave mode the frame is generated externally. Serial Bit Clock (SCLK) SCLK clocks the digital data into DIN and out of DOUT during the frame synchronization interval. The Serial bit clock is generated internally. Reset Function (RESET) The reset function is to initialize the internal counters and control register. A minimum low pulse of 100ns is required to reset the chip. This reset function initiates the serial data communications. The reset function will initialize all the registers to their default value and will put the device in a pre-programmed state. After a low-going pulse on RESET, the device registers will be initialized to provide an over-sampling ratio equal to 160, the serial interface will be in data mode, the DAC attenuation will be set to infinite, the ADC gain will be set to 0dB, the Differential input mode on the ADC converter will be selected, and the multiplexor will be set on the main inputs IN+ and IN-. After a reset condition, the first frame synchronization corresponds to the primary channel. Power Down (PWRDWN) The Power-Down input powers down the entire chip (< 50mW). When PWRDWN Pin is taken low, the device powers down such that the existing internally programmed state is maintained. When PWRDWN is driven high, full operation resumes after 1ms. If the PWRDWN input is not used, it should be tied to VDD. Hardware Control (HC0, HC1) These two pins are used for Hardware/Software Control of the device. The data on HC0 and HC1 will be latched on to the device on the rising edge of the Frame Synchronization Pulse. If these two pins are low, Software Control Mode is selected. When in Software Control Mode, the LSB of the 16-bit word will select the Data Mode (LSB = 0) or the Control Mode (LSB = 1). Other combinations of HC0/HC1 are for Hardware Control. These inputs should be tied low if not used. Rev 9 5/24 Pins description & Block diagram STLC7550 Master/Slave Control (M/S) When M/S is high, the device is in master mode and Fs is generated internally. When M/S is low, the device is in slave mode and Fs must be generated externally. Master Clock Mode (MCM) When MCM is high, XTALIN is provided externally and must be equal to 36.864MHz. When MCM is low, XTALIN is provided externally and must be equal to oversampling frequency : Fs x Over (see Figure 3 and Section 2.4). Timeslot Control (TS) When TS = 0 the data are assigned to the first 16 bits after falling edge of FS (7546 mode) otherwise the data are bits 17 to 32. The case M/S = 1 with TS = 1 is reserved for life-test (transmit gain fixed to 0dB). ) s ( t c u d o ) r s ( P t c e t u e d l o o r s P b e O t e l ) o s ( s t b c u O d o ) r s P ( t c e t u e l d o o r s P b O e t e l o s b O 1.1.3 Clock signals (2 pins) Depending on MCM value, these pins have different function. MCM = 1 (XTALIN, XTALOUT) These pins must be tied to external crystal. For the value of crystal see Section 2.3. MCM = 0 (MCLK, XTALOUT) MCLK Pin must be connected to an external clock. XTALOUT is not used. 1.1.4 Analog interface (9 pins) DAC and ADC Positive Reference Voltage Output (VREFP) This pin provides the Positive Reference Voltage used by the 16-bit converters. The reference voltage, VREF, is the voltage difference between the VREFP and VREFN outputs, and its nominal value is 1.25V. VREFP should be externally decoupled with respect to VCM. DAC and ADC Negative Reference Voltage Output (VREFN) This pin provides the Negative Reference Voltage used by the 16-bit converters, and should be externally decoupled with respect to VCM. Common Mode Voltage Output (VCM) This output pin is the common mode voltage (AVDD - AGND)/2. This output must be decoupled with respect to GND. Non-inverting Smoothing Filter Output(OUT+) This pin is the non-inverting output of the fully differential analog smoothing filter. Inverting Smoothing Filter Output (OUT-) This pin is the inverting output of the fully differential analog smoothing filter. Outputs OUT+ and OUTprovide analog signals with maximum peak-topeak amplitude 2 x VREF, and must be followed by an external two pole smoothing filter. The external filter follows the internal single pole switch capacitor filter. The cutoff frequency of the external filter must be greater 6/24 Rev 9 STLC7550 Pins description & Block diagram than two times the sampling frequency (FS), so that the combined frequency response of both the internal and external filters is flat in the passband. The attenuator of the last output stage can be programmed to 0dB, 6dB or infinite. Non-inverting Analog Input (IN+) This pin is the differential non-inverting ADC input. Inverting Analog Input (IN-) This pin is the differential inverting ADC input. These analog inputs (IN+, IN-) are presented to the Sigma-Delta modulator. The analog input peak-topeak differential signal range must be less than 2 x VREF, and must be preceded by an external single pole anti-aliasing filter. The cut-off frequency of the filter must be lower than one half the oversampling frequency. These filters should be set as close as possible to the IN+ and IN- pins. The gain of the first stage is programmable (see Table 4). ) s ( t c u d o ) r s ( P t c e t u e d l o o r s P b e O t e l ) o s ( s t b c u O d o ) r s P ( t c e t u e l d o o r s P b O e t e l o s b O Non-inverting Auxiliary Analog Input (AUX IN+) This pin is the differential non-inverting auxiliary ADC input. The characteristics are same as the IN+ input. Inverting Auxiliary Analog Input (AUX IN-) This pin is the differential inverting auxiliary ADC input. The characteristics are same as the IN- input. The input pair (IN+/IN- or AUX IN+/AUX IN-) are software selectable. Figure 2. Block diagram HC0 HC1 16 15 29 IN- 30 AUXIN+ 27 ANALOG MODULATOR LOW-PASS (0.425 x sampling frequency) MUX AUXIN- SERIAL PORTS AND CONTROL REGISTER IN+ 28 (0 + 6dB in diff. input) OUT+ 39 OUT- 40 VREFP 19 VREFN 20 VCM 32 DAC 1 BIT ATTEN. 0dB/+6dB/ INFINITE First order differential switched capacitor filter LOW-PASS (0.425 x sampling frequency) 2nd ORDER MODULATOR 7 MCM 45 DOUT 44 DIN 43 TSTD1 42 TS 18 M/S 4 FS 3 SCLK CLOCK GENERATOR 31 AVDD 21 33 AGND1 AGND2 8 9 XTALOUT XTALIN Rev 9 5 6 41 17 DVDD DGND RESET PWRDWN STLC7550 7/24 Functional description STLC7550 2 Functional description 2.1 Transmit D/A section The functions included in the Tx D/A section are detailed hereafter. 16-bit 2's complement data format is used in the DAC channel. 2.1.1 Transmit Low Pass Filters The transmit low pass filter is basically an interpolating filter including a sinx/x correction. It is a combination of Finite Impulse Response filter (FIR) and an Infinite Impulse Response filter (IIR). The digital signal from the serial interface gets interpolated by 2, 3, 4, 5 or 6 x Sampling Frequency (FS) through the IIR filter. The signal is further interpolated by 32 x FS x n (with n equal to 2, 3, 4, 5, 6) through the IIR and FIR filter. The low pass filter is followed by the DAC. The DAC is oversampled at 64, 96, 128, 160, 192 x FS. The oversampling ratio is user selectable. ) s ( t c u d o ) r s ( P t c e t u e d l o o r s P b e O t e l ) o s ( s t b c u O d o ) r s P ( t 2.2 Receive A/D section c e t u e l d o o r s P b O e t e l o s b O 2.1.2 D/A Converter The oversampled D/A converter includes a second order digital noise shaper, a one bit D/A converter and a single pole analog low-pass filter. The attenuation of the last output stage can be programmed to 0dB, +6dB or infinite. The cut-off frequency of the single pole switchcapacitor lowpass is: OCLK fc - 3dB = ---------------------2 10 with OCLK = Oversampling Clock frequency. Continuous-time filtering of the analog differential output is necessary using an off-chip amplifier and a few external passive components. At least 79dB signal to noise plus distortion ratio can obtained in the frequency band of 0.425 x 9.6kHz (with an oversampling ratio equal to 160). The different functions included in the ADC channel section are described below. 16-bit 2's complement data format is used in the ADC. 2.2.1 A/D Converter The oversampled A/D converter is based on a second order sigma-delta modulator. To produce excellent common-mode rejection of unwanted signals, the analog signal is processed differentially until it is converted to digital data. Single-ended mode can also be used. The ADC is oversampled at 64, 96, 128, 160 or 192 x FS. The oversampling ratio is user selectable. At least -85dB SNDR can be expected in the 0.425 x 9.6kHz bandwidth with a -6dBr differential input signal and an oversampling ratio equal to 160. 2.2.2 Receive Low Pass Filter It is a decimation filter. The decimation is performed by two decimation digital filters : one decimation FIR filter and one decimation IIR filter. The purpose of the FIR filter is to decimate 32 times the digital signal coming from the ADC modulator. 8/24 Rev 9 STLC7550 Functional description The IIR is a cascade of 5 biquads. It provides the low-pass filtering needed to remove the noise remaining above half the sampling frequency. The output of the IIR will be processed by the DSP. 2.3 Clock generator The master clock, MCLK is provided by the user thanks to a crystal or external clock generator (see Figure 3). The MCLK could be equal to 36.864MHz (MCM = 1). In that case thanks to the divider M x Q, the STLC7550 is able to generate all V.34bis and 56 Kbps sampling frequencies (see Table 2). ) s ( t c u d o ) r s ( P t c e t u e d l o o r s P b e O t e l ) o s ( s t b c u O d o ) r s P ( t c e t u e l d o o r s P b O e t e l o s b O When MCM = 0, the MCLK must be equal to the oversampling frequency : Fs x OVER (7546 mode). The ADC and DAC are oversampled at the OCLK frequency. OCLK is equal to the shift clock used in the serial interface. The MCLK frequency should be : MCLK = K x Sampling frequency Combination of M, Q and oversampling ratios allows to generate several sampling frequencies. Recommended values for classical modem applications are as follow : Table 2. Sampling Frequencies Generation FQ = 36.864MHz (1) FQ = 18.432MHz FQ = 9.216MHz F (kHz) Note: 1 M Q over M Q over M Q over 16.00 3 6 128 2 4.5 128 1 6 96 13.96 3 5.5 160 - - - - - - 13.71 3 7 128 1 7 192 1 7 96 12.80 3 6 160 2 4.5 160 1 4.5 160 12.00 3 8 128 2 6 128 1 6 128 11.82 3 6.5 160 - - - - - - 10.97 3 7 160 - - - - - - 10.47 4 5.5 160 2 5.5 160 1 5.5 160 10.29 4 7 128 2 7 128 1 7 128 9.60 4 6 160 2 6 160 1 6 160 9.00 4 8 128 2 8 128 1 8 128 8.86 4 6.5 160 2 6.5 160 1 6.5 160 8.23 4 7 160 2 7 160 1 7 160 8.00 4 6 192 2 6 192 1 6 192 7.20 4 8 160 2 8 160 1 8 160 Recommended value. Rev 9 9/24 Functional description Figure 3. STLC7550 Clock Block Diagram XTALIN (MCLK) XTALOUT SCLK MCM (OCLK) M/S Sync VDD /M /Q % OVER Bit 3-4-5 Cont. Reg. : Bit 8-9-10-11-12-13 FS Internal Sampling ) s ( t c u d o ) r s ( P t c e t u e d l o o r s P b e O t e l ) o s ( s t b c u O d o ) r s P ( t c e t u e l d o o r s P b O e t e l o s b O 2.4 Modes of operation Thanks to MCM and M/S programmation pins we can get the following configuration. Configuration 1 : MCM = 1, M/S = 1 The STLC7550 is in master mode and we have : Fs = XTAL IN / (M x Q x OVER) Fs and SCLK are output pins. Figure 4. Configuration 1 fQ = 36.864MHz XTALIN BCLK SCLK FS FS DO DIN DI DOUT M/S VDD MCM VDD TS GND STLC7550 PROCESSOR Configuration 2 : MCM = 1, M/S = 0 The STLC7550 is in slave mode. SCLK is provided by the STLC7550, the processor generates the Fs and controls the phase of the sampling frequency. Fs must be the result of a division of a number of cycles of SLCK (Fs = SCLK % OVER). Configuration 3 : MCM = 0, M/S = 1 The STLC7550 is in master mode and the processor provides the XTAL IN = MCLK = OCLK. The STLC7550 generates the Fs from OCLK. In this mode the configuration 3 is equivalent to the STLC7546 mode. Configuration 4 : MCM = 0, M/S = 0 The STLC7550 is in slave mode. The configuration 4 is equivalent to configuration 3 but the Fs is generated and phase controlled by the processor. 10/24 Rev 9 STLC7550 Functional description Figure 5. Configuration 2 fQ = 36.864MHz XTALIN BCLK SCLK FS FS DO DIN DI M/S MCM TS DOUT GND VDD GND STLC7550 PROCESSOR ) s ( t c u d o ) r s ( P t c e t u e d l o o r s P b e O t e l ) o s ( s t b c u O d o ) r s P ( t c e t u e l d o o r s P b O e t e l o s b O Figure 6. Configuration 3 (7546 mode) fQ = K x Fs XTALIN BCLK SCLK FS FS DO DIN DI PROCESSOR M/S VDD MCM GND TS GND DOUT STLC7550 Configuration 5 : MCM = 1, M/S = 1 (master codec) MCM = 0, M/S = 0 (slave codec) This is dual codec application. The master codec has his data in timeslot 0 and the slave codec has his data in timeslot 1 thanks to the programmation of TS. Figure 7. Configuration 4 fQ = K x Fs XTALIN BCLK SCLK FS FS DO DIN DI DOUT M/S GND MCM GND TS GND STLC7550 PROCESSOR Rev 9 11/24 Functional description Figure 8. STLC7550 Configuration 5 fQ = 36.864MHz XTALIN PROCESSOR BCLK SCLK FS FS DO DIN DI DOUT M/S VDD MCM VDD TS GND STLC7550 HC0 HC1 ) s ( t c u d o ) r s ( P t c e t u e d l o o r s P b 2.5 Host interface e O t e l ) o s ( s t b c u O d o ) r s P ( t c e t u e l d o o r s P b O e t e l o s b O HC0 HC1 XTAKIN VDD TS M/S GND FS MCM GND DIN DOUT STLC7550 The Host interface consist of the shift clock, the frame synchronization signal, the ADCchannel data output, and the DAC-channel data input. Two modes of serial transfer are available : - First : Software mode for 15-bit transmit data transfer and 16-bit receive data transfer - Second : hardware mode for 16-bit data transfer. Both modes are selected by the Hardware Control pins (HC0, HC1). The data to the device, input/output are MSB-first in 2's complement format (see Table 3). When Control Mode is selected, the device will internally generate an additional Frame Synchronization Pulse (Secondary Frame Synchronization Pulse) at the midpoint of the original Frame Period. If the device is in slave mode the additional frame sync (secondary frame sync pulse) must be generated by the processor. The Original Frame Synchronization Pulse will also be referred to as the Primary Frame Synchronization Pulse. Table 3. 12/24 Mode selection HC1 HC0 LSB Useful Data Secondary FSYNC 0 0 0 15bits No Software Mode for Data Transfer only. 0 0 1 15bits (+16bits reg.) Yes Software Mode for Data Transfer + Control Register Transfer. Rev 9 Description STLC7550 Functional description Table 3. Mode selection (continued) HC1 HC0 LSB Useful Data Secondary FSYNC 0 1 X 16bits No Hardware Mode for Data Transfer only. 1 X X 16bits (+16bits reg.) Yes Hardware Mode for Data Transfer + Control Register Transfer. Figure 9. Description Data Mode Sampling period FS ) s ( t c u d o ) r s ( P t c e t u e d l o o r s P b e O t e l ) o s ( s t b c u O d o ) r s P ( t c e t u e l d o o s ControlPrregister b 2.6 O e t e l o s b O SCLK TxDI - - D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 - - - D15 D14 TxDO - - D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 - - - D15 D14 00 or 01 HC1, HC0 Figure 10. Mixed Mode Sampling Period 1/2 Sampling Period (see Note) FS SCLK TxDI Data Word Input Control Word TxDO Data Word Output Register Word HC1, HC0 1X 01 Note : In slave mode, this 1/2 Sampling Period is not mandatory. If 1/2 Sampling Period is not provided, one sample is lost. This section defines the control and device status information. The register programming occurs only during Secondary Frame Synchronization. After a reset condition, the device is always in data mode. Table 4. Bits Assignment Bits Name 0 - 1 2 Function Reset Value - 0 D1 Aux/Main Input 0 D2 Receive Gain 0 Rev 9 13/24 Functional description Table 4. STLC7550 Bits Assignment (continued) Bits Name Function Reset Value 3 D3 Oversampling bit 0 0 4 D4 Oversampling bit 1 0 5 D5 Oversampling bit 2 0 6 D6 Attenuator transmit bit 0 0 7 D7 Attenuator transmit bit1 0 8 M M Divider 1 9 Q0 Q0 Divider 1 10 Q1 Q1 Divider 0 11 Q2 Q2 Divider 0 12 T0 M Divider and Test mode bit 0 0 13 T1 M Divider and Test mode bit 1 0 14 TEST2 Test mode bit 2 0 15 TEST3 Test mode bit 3 0 ) s ( t c u d o ) r s ( P t c e t u e d l o o r s P b e O t e l ) o s ( s t b c u O d o ) r s P ( t c e t u e l d o o r s P b O e t e l o s b O Table 5. Aux/Main Input D1 Function 0 Main Receive Input 1 Auxiliary Receive Input Table 6. Receive Gain D2 Function DIFFERENTIAL INPUT 0 0dB gain (commun mode fixed) 1 +6dB gain (commun mode non-fixed) SINGLE ENDED (one input used, other at VCM) Note: 1 0 -6dB gain (see Note 1) 1 0dB gain Not recommended case. Performances could be reduced. Table 7. 14/24 Oversampling Ratio D5 D4 D3 Function 0 0 0 160 0 0 1 192 0 1 0 Reserved 0 1 1 Reserved Rev 9 STLC7550 Functional description Table 7. Oversampling Ratio (continued) D5 D4 1 0 0 Reserved 1 0 1 64 1 1 0 96 1 1 1 128 Table 8. D3 Function Transmit Attenuation D7 D6 Function 0 0 Infinite 0 1 Reserved 1 0 -6dB 1 1 0dB ) s ( t c u d o ) r s ( P t c e t u e d l o o r s P b e O t e l ) o s ( s t b c u O d o ) r s P ( t c e t u e l d o o r s P b O e t e l o s b O Table 9. Q Divider Clock Generator D11 D10 D9 0 0 0 Q divider = 5 0 0 1 Q divider = 6 0 1 0 Q divider = 7 0 1 1 Q divider = 8 1 0 0 Q divider = 4.5 1 0 1 Q divider = 5.5 1 1 0 Q divider = 6.5 1 1 1 Q divider = 7.5 Table 10. Function M Divider Clock Generator D13 D12 D8 0 0 0 M divider = 3 0 0 1 M divider = 4 0 1 X Reserved 1 0 X Reserved 1 1 0 M divider = 1 1 1 1 M divider = 2 Table 11. Function Reserved Mode D15 D14 X X Function Reserved for test This two bits must be set to 0 for normal operation. Rev 9 15/24 Electrical Specifications 3 STLC7550 Electrical Specifications Unless otherwise noted, Electrical Characteristics are specified over the operating range. Typical values are given for VDD = 3V, Tamb = 25C and for nominal Master clock frequency MCLK = 1.536MHz and oversampling ratio = 160. 3.1 Absolute maximum ratings Table 12. Absolute Maximum Ratings (referenced to GND) ) s ( t c u d o ) r s ( P t c e t u e d l o o r s P b e O t e l ) o s ( s 3.2 Nominal DC Characteristics t b c u O d o ) r s P ( t c e t u e l d o o r s P b O e t e l o s b O Symbol VDD Unit -0.3, 7.0 V Digital or Analog Input Voltage -0.3, VDD+0.3 V II,IIN Digital or Analog Input Current 1 mA IO Digital Output Current 20 mA IOUT Analog Output Current 10 mA Toper Operating Temperature 0, 70 C Tstg Storage Temperature -40, 125 C Maximum Power Dissipation 200 mW Electrostatic Discharge 2000 V ESD Nominal DC Characteristics (VDD = 3V 5%, GND = 0V, TA = 0 to 70C unless otherwise specified) Symbol VDD DC Supply Voltage Value VI,VIN PDMAX Table 13. Parameter Parameter Supply Voltage Range Min. Typ. Max. Unit 2.70 3 5.5 V POWER SUPPLY AND COMMON MODE VOLTAGE SINGLE POWER SUPPLY (DVDD= AVDD) IDDA Analog Supply Current 6 mA IDDD Digital Supply Current 4 mA IDD-LP VCM Supply Current in Low Power Mode MCLK Stopped MCLK Running Output Common Mode Voltage VCM Output Voltage Load Current (see Note 1) VDD/2-5% 1 200 10 A VDD/2 VDD/2+5% V 0.5 V DIGITAL INTERFACE 16/24 VIL Low Level Input Voltage -0.3 VIH High Level Input Voltage DVDD-0.5 Rev 9 V STLC7550 Table 13. Electrical Specifications Nominal DC Characteristics (continued) (VDD = 3V 5%, GND = 0V, TA = 0 to 70C unless otherwise specified) Symbol Parameter II Input Current VI = VDD or VI = GND VOH High Level Output Voltage (ILOAD= -600A) VOL Low Level Output Voltage (ILOAD= 800A) Min. Typ. Max. Unit -10 1 10 A DVDD-0.5 V 0.3 V 1.35 V ANALOG INTERFACE Differential Reference Voltage Output VREF = (VREFP- VREFN) VREF Tcoeff (VREF) 1.15 VREF Temperature Coefficient 1.25 200 ppm/C ) s ( t c u d o ) r s ( P t c e t u e d l o o r s P b e O t e l ) o s ( s t b c u O d o ) r s P ( t c e t u e l d o o r s P b O3.3 Nominal e AC Electrical Characteristics t e l o s b O VCMO IN Input Common Mode Offset Voltage VCMO IN = [(IN+)+(IN-)]/2 -VCM VDIF IN Differential Input Voltage : [(IN+)-(IN-)] 2 x VREF VOFF IN Differential Input DC Offset Voltage -100 100 mV VCMO OUT Output Common Mode Voltage Offset : (OUT+ + OUT-)/2 - VCM (see Note 1) -20 20 mV VDIF OUT Differential Output Voltage : OUT+ - OUT- 2 x VREF VOFF OUT Differential Output DC Offset Voltage : (OUT+ -OUT-) (0000x) -100 RIN Input Resistance IN+, IN- (id. AUX IN) 100 ROUT Load Resistance (OUT+, OUT-) CL Load Capacitance (OUT+, OUT-) Note: 1 Table 14. Symbol 100 2 x VREF V 100 mV k 50 W 10 Output A/D Modulator Voltage Offset: IN+ = IN- = VCM mV Vpp 2 x VREF Output Resistance (OUT+, OUT-) RL VADO OUT -100 k -1000 20 pF +1000 LSB Device is very sensitive to noise on VCM Pin. VCM output voltage load current must be DC (<10A). in order to drive dynamic load, VCM must be buffered. AC variation in VCM current magnitude decrease A/D and D/A performance. Nominal AC Electrical Characteristics (Reference level VIL = 0.5V, VIH = DVDD - 0.5V, VOL = 0.3V, VOH = DVDD - 0.5V, DVDD = 3V, Output load = 50pF unless otherwise) N Parameter Min. Typ. Max. Unit SERIAL CHANNEL TIMING (see Figure 11 for Parameter numbers) 1 SCLK Period 300 ns 2 SCLK Width Low 150 ns Rev 9 17/24 Electrical Specifications Table 14. STLC7550 Nominal AC Electrical Characteristics (continued) (Reference level VIL = 0.5V, VIH = DVDD - 0.5V, VOL = 0.3V, VOH = DVDD - 0.5V, DVDD = 3V, Output load = 50pF unless otherwise) Symbol N Parameter Min. Typ. Max. 150 Unit 3 SCLK Width High ns 4 SCLK Rise Time 10 ns 5 SCLK Fall Time 10 ns 6 FS Setup 100 ns 7 FS Hold 100 ns 8 DIN Setup 50 ns 9 DIN Hold 0 ns 10 DOUT Valid 11 HC0,HC1 Set-up ) s ( t c u d o ) r s ( P t c e t u e d l o o r s P b e O t e l ) o s ( s t b c u O d o ) r s P ( t c e t u e l d o o r s P b O e t e l o s b O 20 20 12 ns ns 0 50 ns 2.8 MHz 55 % MASTER CLOCK INTERFACE (MCLK) (MCM = 0) MCLK Master Clock Input 0.92 Master Clock Duty Cycle 45 Figure 11. Serial Interface Timing Diagram 1 12 2.4 3 5 SCLK 6 7 FS 8 DIN 9 MSB 10 DOUT MSB 11 HC0 18/24 Rev 9 1.54 STLC7550 Electrical Specifications 3.4 Transmit Characteristics 3.4.1 Performance of the Tx channel Table 15. Symbol Gabs Performance of the Tx channel Typical values are given for AVDD = 3V, Tamb = 25C and for nominal master clock MCLK = 1.536MHz, differential mode and oversampling ratio = 160. Measurement band = 100Hz to 0.425 x Sampling frequency. Parameter Absolute Gain at 1kHz Min. Typ. Max. Unit -0.5 0 0.5 dB ) s ( t c u d o ) r s ( P t c e t u e d l o o r s P b e O t e l ) o s ( s t b c 3.5 Receive Characteristics u O d o ) r s P ( t c e t u e l d o o r s P b O e t e l o s b O Ripple Note: 3.4.2 1 Ripple in Band : 0 to 0.425 x FS 0.2 dB -92 dB THD Total Harmonic Distortion (differential Tx signal : VOUT = 1.25VPP, f = 1kHz) DR Dynamic Range (f = 1kHz) (measured over the full 0 to FS/2 with a -20dBr output signal and extrapolated to full scale) (see Note 1) 87 dB CRxTx Crosstalk (transmit channel to receive channel) 85 dB -85 DR - 1.76 The dynamic range can be measured in bit with : Nbit = -------------------------- with DR in dB. 6.02 Smoothing filter transfer characteristics The cut-off frequency of the single pole switch-capacitor low-pass filter following the DAC is : n 32 FS fc - 3dB = --------------------------- with n = 2, 3, 4, 5, 6 (see Section 2.1.1). 2 10 3.5.1 Performance of the Rx channel Table 16. Symbol Performance of the Rx channel Typical values are given for AVDD = 3V, Tamb = 25C and for nominal master clock MCLK = 1.536MHz, differential mode and oversampling ratio = 160. Measurement band = 100Hz to 0.425 x Sampling frequency. Parameter Gabs Absolute Gain at 1kHz Ripple Ripple in Band : 0 to 0.425 x FS Min. Typ. Max. Unit -0.5 0 0.5 dB 0.2 dB -92 dB THD Total Harmonic Distortion (differential Tx signal : VOUT = 1.25VPP, f = 1kHz) DR Dynamic Range (f = 1kHz) (measured over the full 0 to FS/2 with a -20dBr output signal and extrapolated to full scale) (see Note 2) 87 dB CRxTx Crosstalk (transmit channel to receive channel) 85 dB Rev 9 -85 19/24 Typical application 4 STLC7550 Typical application Figure 12. Line Interface - Differential Duplexor 22k 100pF 13.2k C : Improve the low frequency response. Its value depends on the transformer inductance. C' : Reduces the DC offset gain. Z0 : Nominal line impedance 22k Z0/2 OUT+ C VCM 680pF 13.2k 2R Z0/2 22k Phone Line ) s ( t c u d o ) r s ( P t c e t u e d l o o r s P b e O t e l ) o s ( s t b c u O d o ) r s P ( t c e t u e l d o o r s P b O e t e l o s b O OUT- C 22k 100pF 2R R 1.2k IN+ 2.2nF R' VCM r 2.2nF C' R' 1.2k R IN- All capacitor, resistor and impedance values are provided for indication only. These values must be readjusted according to line transformer characteristics and also telecommunication regulations in force in individual countries. Refer to Application Note AN930 for more detailed information. Contact your local representative. 20/24 Rev 9 STLC7550 5 Definition and Terminology Definition and Terminology Data Transfer Interval The time during which data is transfered from DOUTand to DIN. This interval is 16 shift clocks provides by the chip. Signal Data This refers to the input signal and all the converted representations through the ADC channel and the DAC channel. Data Mode This refers to the data transfer. Since the device is synchronous, the signal data words from the ADC channel and to the DAC channel occur simultaneously. ) s ( t c u d o ) r s ( P t c e t u e d l o o r s P b e O t e l ) o s ( s t b c u O d o ) r s P ( t c e t u e l d o o r s P b O e t e l o s b O Control Mode This refers to the digital control data transfer into DIN and the register read data from DOUT. The control mode interval occurs when requested by hardware or software. Frame Sync. Frame sync refers only to the falling edge of the signal which initiates the data transfer interval. The primary frame sync starts the Data Mode and the secondary frame sync starts the Control Mode. Frame Sync and Sampling The time between falling edges of successive primary frame Period sync signals. ADC Channel This term refers to all signal processing circuits between the analog input and the digital conversion result at DOUT. DAC Channel This term refers to all signal processing circuits between the digital data word applied to DINand the differential output analog signal available at OUT+ and OUT-pins. OverSampling Ratio This term refer to the ratio between the master clock MCLK corresponding to the oversampling frequency and the sampling frequency FS. Resolution The number of bits in the input words to the DAC, and the output words in the ADC. Dynamic Range The S/(N+D) with a 1kHz, -20dBr input signal and extrapolated to full scale. Use of a small input signal reduces the harmonic distortion components of the noise to insignificance. Units in dB or in Nbitas explained before. Signal-to(Noise+Distortion) S/(THD+N) is the ratio of the rms of the input signal to the rms of all other spectral components within the measurement bandwidth (0.425 x Sampling Frequency). Units in dB. Crosstalk The amount of 1kHz signal present on the output of the grounded input channel with 1kHz 0dB signal present on the other channel. Units in dB. Power Supply Rejection Ratio PSRR. The amount of 1kHz signal present on the output of the grounded input channel with 1kHz 200mVPPsignal present on the power supply. Rev 9 21/24 Package information 6 STLC7550 Package information In order to meet environmental requirements, ST offers these devices in ECOPACK(R) packages. These packages have a Lead-free second level interconnect. The category of second Level Interconnect is marked on the package and on the inner box label, in compliance with JEDEC Standard JESD97. The maximum ratings related to soldering conditions are also marked on the inner box label. ECOPACK is an ST trademark. ECOPACK specifications are available at: www.st.com. Figure 13. TQFP48 (7 x 7 x 1.4mm) Mechanical Data & Package Dimensions ) s ( t c u d o ) r s ( P t c e t u e d l o o r s P b e O t e l ) o s ( s t b c u O d o ) r s P ( t c e t u e l d o o r s P b O e t e l o s b O mm DIM. MIN. TYP. A A1 inch MAX. MIN. TYP. 1.60 0.05 0.15 MAX. OUTLINE AND MECHANICAL DATA 0.063 0.002 0.006 A2 1.35 1.40 1.45 0.053 0.055 0.057 B 0.17 0.22 0.27 0.006 0.008 0.010 C 0.09 0.20 0.004 0.008 D 9.00 0.354 D1 7.00 0.276 D3 5.50 0.217 e 0.50 0.020 E 9.00 0.354 E1 7.00 0.276 E3 5.50 0.217 Body: 7 x 7 x 1.40mm L 22/24 0.45 0.60 0.75 0.018 0.024 L1 1.00 K 0(min.), 3.5(typ.), 7(max.) 0.030 0.039 Rev 9 TQFP48 STLC7550 7 Revision history Revision history Table 17. Document revision history Date Revision Changes 14-Jan-2004 8 Initial release. 06-Feb-2006 9 Removed the TQFP44 package and the respective ordering part number. Inserted the new part number E-STLC7550TQF7 (ECOPACK). ) s ( t c u d o ) r s ( P t c e t u e d l o o r s P b e O t e l ) o s ( s t b c u O d o ) r s P ( t c e t u e l d o o r s P b O e t e l o s b O Rev 9 23/24 STLC7550 ) s ( t c u d o ) r s ( P t c e t u e d l o o r s P b e O t e l ) o s ( s t b c u O d o ) r s P ( t c e t u e l d o o r s P b O e t e l o s b O Please Read Carefully: Information in this document is provided solely in connection with ST products. STMicroelectronics NV and its subsidiaries ("ST") reserve the right to make changes, corrections, modifications or improvements, to this document, and the products and services described herein at any time, without notice. All ST products are sold pursuant to ST's terms and conditions of sale. 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