AK4254VF - AKM Semiconductor, Inc.

[AK4254]

MS0586-E-01 2007/08

- 1 -

GENERAL DESCRIPTION

The AK4254 is a 2ch Video AMP with 7:2 video switch, input clamp circuit, LPF and charge pump circuit.

The integrated charge pump circuit can generate the negative power supply and remove the output

coupling capacitor. The AK4254 suits Car Navigation system. The AK4254 is offered in a space saving

30pin VSOP package.

FEATURES

1. Video Section

• Composite Signal Inputs/Output

• Selector for 7 inputs and 2 outputs

• Video Driver for Composite Signal Output (+6dB)

• On-Chip Sync-tip Clamp Circuit

• 6MHz Low Pass Filter

• Charge pump circuit for negative power supply

• Parallel I/F or Serial µP I/F (I2C, 3-wi res serial)

2. Power Supply: 2.7V ~ 3.6V

3. Ta=-40 ∼ +85°C

4. Package: 30pin VSOP

1uF 1uF

PDN

P/S

I2C/SEL22

CDTI/SDA/S E L21

CCLK/SCL/SEL20

CSN/SEL12

CAD1/SEL11

CAD0/SEL10

VIN1

VIN2

VIN3

VIN4

VIN5

VIN6

VIN7

+6dB

Control

I/F

SW1

SW2

0.1uF

VOUT1

VOUT2

Charge

Pump

Clock

Generator

CP2 CN2 CVEE2 CVSS2

+6dB

0.1uF

Clock

Generator

Charge

Pump

CP1

AVDD

AVSS

TEST

CVDD2 1uF 1uF

Sync-tip

Clamp

LPF

CVSS1 CVEE1 CN1 CVDD1

Figure 1. Block Diagram

Capacitor-less Video Amp with 7:2 Video Switch

AK4254

[AK4254]

MS0586-E-01 2007/08

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■ Ordering Guide

AK4254VF -40 ∼ +85°C 30pin VSOP

AKD4254 Evaluation board for AK4254

■ Pin Layout

1 CVDD1

CP1

CVSS1

CVEE1

VOUT1

AVSS 8

CVDD2

CP2

CN2

CVSS2

CVEE2

VOUT2

PDN

AK4254

Top

View

9 TEST

P/S

VIN1 11

VIN2 12

I2C/SEL22

CDTI/SDA/SEL21

CCLK/SCL/SEL20

CSN/SEL12

AVDD

VIN3 13

VIN4 14

CAD1/SEL11

CAD0/SEL10

VIN5 15 VIN6 16

VIN7

CN1

[AK4254]

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PIN/FUNCTION

No. Pin Name I/O Function

1 CVDD1 -

Charge Pump Power Supply pin, 2.7V∼3.6V

2 CP1 O

Positive Charge Pump Capacitor Terminal 1 Pin.

Connect to CN1 with a 1.0μF capacitor that has the low ESR (Equivalent Series

Resistance) over all temperature range. When this capacitor has the polarity, the

positive polarity pin should be connected to the CP pin. Non polarity capacitors can also

be used.

3 CN1 I

Negative Charge Pump Capacitor Terminal 1 Pin

Connect to CP1 with a 1.0μF capacitor that has the low ESR (Equivalent Series

Resistance) over all temperature range. When this capacitor has the polarity, the

positive polarity pin should be connected to the CP pin. Non polarity capacitors can also

be used.

4 CVSS1 -

Charge Pump Ground Pin, 0V

Connect to VEE1 with a 1.0μF capacitor that has the low ESR (Equivalent Series

Resistance) over all temperature range. When this capacitor has the polarity, the

positive polarity pin should be connected to the CVSS1 pin. Non polarity capacitors can

also be used.

5 CVEE1 O

Negative Voltage Output Pin for Video Amplifier 1

Connect to CVSS1 with a 1.0μF capacitor that has the low ESR (Equivalent Series

Resistance) over all temperature range. When this capacitor has the polarity, the

positive polarity pin should be connected to the CVSS1 pin. Non polarity capacitors can

also be used.

6 VOUT1 O Video Output #1 Pin

7 AVDD -

Analog Power Supply Pin, 2.7V∼3.6V

8 AVSS - Analog Ground Pin, 0V

9 TEST I

Test Pin

This pin should be connected to AVSS.

10 P/S I

Parallel/Serial Control Mode Pin

“L”: Serial Control Mode, “H”: Parallel Control Mode

11 VIN1 I Video Input #1 Pin

12 VIN2 I Video Input #2 Pin

13 VIN3 I Video Input #3 Pin

14 VIN4 I Video Input #4 Pin

15 VIN5 I Video Input #5 Pin

16 VIN6 I Video Input #6 Pin

17 VIN7 I Video Input #7 Pin

CAD0 I Chip Address 0 in Serial Control Mode

18 SEL10 I Input Selector 1 Control #0 Pin in Parallel Control Mode

CAD1 I Chip Address 1 in Serial Control Mode

19 SEL11 I Input Selector 1 Control #1 Pin in Parallel Control Mode

CSN I

Chip Select Pin in Serial Control Mode, I2C pin = “L”

This pin should be connected to AVSS in Serial Control Mode. I2C pin =“H”

SEL12 I Input Selector 1 Control #2 Pin in Parallel Control Mode.

CCLK I Control Data Clock Pin in Serial Control Mode, I2C pin = “L”

SCL I Control Data Clock Pin in Serial Control Mode, I2C pin = “H”

SEL20 I Input Selector 2 Control #0 Pin in Parallel Control Mode

CDTI I Control Data Input Pin in Serial Control Mode, I2C pin = “L”

SDA I/O Control Data Pin in Serial Control Mode, I2C pin = “H”

SEL21 I Input Selector 2 Control #1 Pin in Parallel Control Mode.

I2C I

Control Mode Select Pin in Serial Control Mode

“L”: 3-wire Serial Mode, “H”: I2C Bus mode 23

SEL22 I Input Selector 2 Control #2 Pin in Parallel Control Mode

[AK4254]

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No. Pin Name I/O Function

24 PDN I

Power-Down Mode Pin

When at “L”, the AK4254 is in the power-down mode and held in reset, the AK4254

must always be reset upon power-up in Serial Control Mode (P/S pin= “L”).

25 VOUT2 O Video Output #2 Pin.

26 CVEE2 O

Negative Voltage Output Pin for Video Amplifier 2

Connect to CVSS2 with a 1.0μF capacitor that has the low ESR (Equivalent Series

Resistance) over all temperature range. When this capacitor has the polarity, the

positive polarity pin should be connected to the CVSS2 pin. Non-polarity capacitors can

also be used.

27 CVSS2 -

Charge Pump Ground Pin, 0V

Connect to CVEE2 with a 1.0μF capacitor that has the low ESR (Equivalent Series

Resistance) over all temperature range. When this capacitor has the polarity, the

positive polarity pin should be connected to the CVSS2 pin. Non-polarity capacitors can

also be used.

28 CN2 I

Negative Charge Pump Capacitor Terminal 2 Pin

Connect to CP2 with a 1.0μF capacitor that has the low ESR (Equivalent Series

Resistance) over all temperature range. When this capacitor has the polarity, the

positive polarity pin should be connected to the CP2 pin. Non polarity capacitors can

also be used.

29 CP2 O

Positive Charge Pump Capacitor Terminal 2 Pin

Connect to CN2 with a 1.0μF capacitor that has the low ESR (Equivalent Series

Resistance) over all temperature range. When this capacitor has the polarity, the

positive polarity pin should be connected to the CP2 pin. Non polarity capacitors can

also be used.

30 CVDD2 -

Charge Pump Power Supply Pin, 2.7V∼3.6V

Note: All digital input pins (CADO/SEL10, CADT/SEL11, CSN/SEL12, CCLK/SCL/SEL20, CDTI/SDA/SEL21,

I2C/SEL22) must not be left floating.

■ Handling of Unused Pin

The unused I/O pins should be processed appropriately as below.

Classification Pin Name Setting

Analog VIN1-7 These pins should be open.

Digital CSN/SEL12 These pins should be connected to AVDD or AVSS.

ASAHI KASEI [AK4254]

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ABSOLUTE MAXIMUM RATINGS

(AVSS=CVSS1=CVSS2=0V; Note: 1)

Parameter Symbol min max Units

Power Supply (Note: 2) AVDD

CVDD1

CVDD2

-0.3

4.0

Input Current (any pins except for supplies) IIN - ±10 mA

Input Voltage (Note: 3)

(VIN1-7, I2C/SEL22, CDTI/SDA/SEL21,

CCLK/SCL/SEL20, CSN/SEL12,

CAD1/SEL11, CAD0/SEL10, PDN, P/S pins)

VIN -0.3 AVDD+0.3

or 4.0

Ambient Operating Temperature Ta -40 85 °C

Storage Temperature Tstg -65 150 °C

Note: 1. All voltages are with respect to ground.

Note: 2. AVSS, CVDSS1 and CVSS2 must be connected to the same analog ground plane.

Note: 3. The external pull-up resistors at the SDA and SCL pins should be connected to the maximum voltage or less.

Max is smaller value between AVDD+0.3V and 4.0V.

The voltage must not be applied to the CN1 and CN2 pins.

WARNING: Operation at or beyond these limits may result in permanent damage to the device.

Normal operation is not guaranteed at these extremes.

RECOMMENDED OPERATING CONDITIONS

(AVSS=CVSS1=CVSS2=0V; Note: 1)

Parameter Symbol Min Typ max Units

AVDD 2.7 3.0 3.6 V Power Supply (Note: 4)

CVDD1, CVDD2 AVDD V

Note: 4. AVDD, CVDD1 and CVDD2 must be the same voltage.

*AKEMD assumes no responsibility for the usage beyond the conditions in this datasheet.

DIGITAL CHARACTERISTICS

(Ta = -40∼85°C; AVDD=CVDD1=CVDD2=2.7V∼3.6V)

Parameter Symbol min typ max Units

High-Level Input Voltage

Low-Level Input Voltage

VIH

VIL

70%AVDD

30%AVDD

Low-Level Output Voltage

(SDA pin: Iout= 3mA)

VOL - - 0.4 V

Input Leakage Current Iin - - ± 10 μA

ASAHI KASEI [AK4254]

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ANALOG CHARACTERISTICS

(Ta = 25°C; AVDD=CVDD1=CVDD2=3.0V; unless otherwise specified. Note: 5, Note: 6)

Parameter Conditions min typ max Units

Gain Input=0.3Vp-p, 100kHz 5.3 6 6.7 dB

Response at 6MHz -2.0 +2.0 dB

Response at 27MHz -40 -20 dB

Frequency Response

Input=0.3Vpp, Sin Wave

(0dB at 100kHz)

Group Delay Distortion |GD3MHz - GD6MHz| 10 100 ns

Dynamic Output Signal f=100kHz, maximum with distortion < 1.0%. 2.52 Vpp

Inter channel Isolation f=4.43MHz, 1Vp-p input - 65 - dB

S/N Reference Level = 0.7Vp-p,

BW= 100kHz to 6MHz.

- 65 - dB

Differential Gain 0.7Vpp 5steps modulated staircase.

Chrominance & burst are 280mVpp, 4.43MHz.

- +0.4 - %

Differential Phase 0.7Vpp 5steps modulated staircase.

Chrominance & burst are 280mVpp, 4.43MHz.

- +2.5 - Degree

Load Resistance R1+R2 (Note: 9) 140 150 - Ω

Load Capacitance C1 (Note: 9)

C2 (Note: 9)

400

Power Supply Current

Normal Operation

(PDN pin = “H”, Note: 7)

AVDD+CVDD1+CVDD2 20 30 mA

Power-Down Mode

(PDN pin = “L”, Note: 8)

AVDD+CVDD1+CVDD2

10 100

μA

Note: 5. Video analog characteristics are measured at the pin directly.

Note: 6. Input Sync Tip Level=-0.43V∼-0.14V (It is the difference with Pedestal Level and Sync Tip Level.)

Horizontal Line Sync Pulse=4.0μs ∼5.4μs, Equalizing Pulse=2.0μs ∼2.7μs, Serration Pulse=4.0μs ∼5.4μs

Note: 7. VIN Black level input, no load

Note: 8. All digital input pins (P/S, I2C/SEL22, CDTI/SDA/SEL21, CCLK/SCL/SEL20, SN/SEL12, CAD1/SEL11,

CAD0/SEL10) are held at AVSS.

Note: 9. Refer to the Figure 2.

VOUT

75 Ω

max: 400pF

(C1)

max: 15pF

(C2)

Figure 2. Load Resistance R1+R2 and Load Capacitance C1/C2

ASAHI KASEI [AK4254]

MS0586-E-01 2007/08

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SWITCHING CHARACTERISTICS

(Ta =-40∼85°C; AVDD=CVDD1=CVDD2=2.7V∼3.6V; CL = 20pF)

Parameter Symbol Min typ max Units

Control Interface Timing (3-wire Serial mode)

PDN “↑” to CSN “↓”

CCLK Period

CCLK Pulse Width Low

Pulse Width High

CDTI Setup Time

CDTI Hold Time

CSN “H” Time

CSN “↓” to CCLK “↑”

CCLK “↑” to CSN “↑”

tPDCS

tCCK

tCCKL

tCCKH

tCDS

tCDH

tCSW

tCSS

tCSH

150

200

150

Control Interface Timing (I2C Bus mode):

SCL Clock Frequency

PDN “↑” to SDA “↓” @SCL = “H”

Bus Free Time Between Transmissions

Start Condition Hold Time

(Prior to first clock pulse)

Clock Low Time

Clock High Time

Setup Time for Repeated Start Condition

SDA Hold Time from SCL Falling (Note: 10)

SDA Setup Time from SCL Rising

Rise Time of Both SDA and SCL Lines

Fall Time of Both SDA and SCL Lines

Setup Time for Stop Condition

Pulse Width of Spike Noise

Suppressed by Input Filter

Capacitive load on bus

fSCL

tPDSD

tBUF

tHD:STA

tLOW

tHIGH

tSU:STA

tHD:DAT

tSU:DAT

tSU:STO

tSP

1.3

0.6

1.3

0.6

0.1

0.6

400

0.3

400

kHz

μs

Reset Timing

PDN Pulse Width (Note: 11)

tPD

150

Note: 10. Data must be held for sufficient time to bridge the 300 ns transition time of SCL.

Note: 11. In Serial Control Mode (P/S pin= “L”), it is recommended that the AK4254 is powered up at the PDN pin=“L”.

In Parallel Control Mode, resetting by the PDN pin = “L” is not needed when power up.

Note: 12. I2C is a registered trademark of Philips Semiconductors.

ASAHI KASEI [AK4254]

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■ Timing Diagram

tCCKL

CSN

CCLK

tCDS

CDTI

tCDH

tCSS

C0 A4

tCCKH

R/W

VIH

VIL

VIH

VIL

VIH

VIL

tCCK

VIH

VIL

PDN

tPDCS

WRITE Command Input Timing (3-wire Serial mode)

tCSW

CSN

CCLK

CDTI D2 D0

tCSH

D1 D3

VIH

VIL

VIH

VIL

VIH

VIL

WRITE Data Input Timing (3-wire Serial mode)

tHIGH

SCL

SDA VIH

tLOW

tHD:STA

tR tF

tHD:DAT tSU:DAT tSU:STA

Start Start

VIL

VIH

VIL

PDN VIH

VIL

tPDSD

I2C Bus Mode Timing 1

ASAHI KASEI [AK4254]

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tHIGH

SCL

SDA VIH

tLOW

tBUF

tHD:STA

tR tF

tHD:DAT tSU:DAT tSU:STA

Stop Start Start Stop

tSU:STO

VIL

VIH

VIL

tSP

I2C Bus Mode Timing 2

tPD

VIL

PDN VIH

Power down & Reset timing

ASAHI KASEI [AK4254]

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OPERATION OVERVIEW

■ System Reset

In Serial Control Mode (P/S pin= “L”), it is recommended that AK4254 is powered up when the PDN pin= “L”. If the

AK4254 is powered up when the PDN pin = “H”, the AK4254 should be reset by the PDN pin = “L” after power up. The

control registers are initialized to their default values by resetting. In Parallel Control Mode, resetting by the PDN pin =

“L” is not needed when power up.

■ Parallel Control Mode (P/S pin = “H”)

The AK4524 is in Parallel Control Mode at P/S pin = “H”. When the AK4524 is in Parallel Control Mode, all registers

can not be accessed.

Mode PDN pin SEL12-10 pin CVEE1 pin VOUT1 pin

Power Down mode L x GND GND

H “LLL” GND GND

Normal mode H Except for

“LLL”

-CVDD1 Video signal

output

(x: Don’t Care)

Table 1. VOUT1 mode setting (Parallel Control Mode)

Mode PDN pin SEL22-20 pin CVEE2 pin VOUT2 pin

Power Down mode L x GND GND

H “LLL” GND GND

Normal mode H Except for

“LLL”

-CVDD1 Video signal

output

(x: Don’t Care)

Table 2. VOUT2 mode setting (Parallel Control Mode)

(a) Power Down mode (PDN pin= “L”)

The AK4524 is in Power Down mode at the PDN pin = “L”. When the AK4524 is in the Power Down mode, the

VOUT1-2 outputs are “GND”.

(b) Normal mode (PDN pin= “H”)

The AK4524 have 7:2 video switches. In Parallel Control Mode, the each input of VOUT1-2 is set by SEL12-10 pins and

SEL22-20 pins.

SEL12 pin SEL11 pin SEL10 pin VOUT1 pin

L L L Off Note: 13)

L L H VIN1

L H L VIN2

L H H VIN3

H L L VIN4

H L H VIN5

H H L VIN6

H H H VIN7

Note: 13. When the input setting is “Off”, VOUT1 output is “GND”.

Table 3. Input Selector 1 (Parallel Control Mode)

ASAHI KASEI [AK4254]

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SEL22 pin SEL21 pin SEL20 pin VOUT2 pin

L L L Off Note: 14)

L L H VIN1

L H L VIN2

L H H VIN3

H L L VIN4

H L H VIN5

H H L VIN6

H H H VIN7

Note: 14. When the input setting is “Off”, VOUT2 output is “GND”.

Table 4. Input Selector 2 (Parallel Control Mode)

■ Serial Control Mode (P/S pin = “L”)

The AK4524 is in Serial Control Mode at P/S pin = “L”.

Mode PDN pin SEL 12-10 bit CVEE1 pin VOUT1 pin

Power Down mode L x GND GND

H “000” GND GND

Normal mode H Except for

“000” -CVDD1 Video signal output

(x: Don’t Care)

Table 5. VOUT1 mode setting (Serial Control Mode)

Mode PDN pin SEL 22-20 bit CVEE2 pin VOUT2 pin

Power Down mode L x GND GND

H “000” GND GND

Normal mode H Except for

“000” -CVDD1 Video signal output

(x: Don’t Care)

Table 6. VOUT2 mode setting (Serial Control Mode)

(a) Power Down mode (PDN pin= “L”)

When PDN pin =“L”, the register is reset and the AK4254 is in Power Down mode. When the AK4524 is in the Power

Down mode, the VOUT1-2 outputs are “GND”.

(b) Normal mode (PDN pin= “H”)

The AK4524 have 7:2 video switches. In the Serial Control Mode, the each input of VOUT1-2 is set by SEL12-10 bits

and SEL22-20 bits.

SEL12 bit SEL11 bit SEL10 bit VOUT1 pin

0 0 0 Off Note: 15) (default)

0 0 1 VIN1

0 1 0 VIN2

0 1 1 VIN3

1 0 0 VIN4

1 0 1 VIN5

1 1 0 VIN6

1 1 1 VIN7

Note: 15. When the input setting is “Off”, VOUT1 output is “GND”.

Table 7. Input Selector 1 (Serial Control Mode)

ASAHI KASEI [AK4254]

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SEL22 bit SEL21 bit SEL20 bit VOUT2 pin

0 0 0 Off Note: 16) (default)

0 0 1 VIN1

0 1 0 VIN2

0 1 1 VIN3

1 0 0 VIN4

1 0 1 VIN5

1 1 0 VIN6

1 1 1 VIN7

Note: 16. When the input setting is “Off”, VOUT2 output is “GND”.

Table 8. Input Selector 2 (Serial Control Mode)

■ Video Block

The Video Amp has drivability for a load resistance of 150Ω. The AK4254 has composite input and output with low pass

filter (LPF). Internal negative power supply circuit supplies the negative voltage to the video amp and the video amp 0V

output is used for a pedestal level. Therefore, the output coupling capacitor can be removed.

The negative power supply circuit needs capacitors of Ca and Cb with 1.0μ, which should have the low ESR (Equivalent

Series Resistance). When those capacitors have the polarity, each positive polarity pins should be connected to CP and

VSS side.

The negative power supply circuit generates the negative voltage to use the clock that corresponds to the input video

signal. When there is no video input signal and the negative voltage is insufficient (CVEE > -0.8V) in case of low quality

input signal (Note: 17), the negative power supply circuit generates the negative voltage by using the internal oscillator

circuit. The VOUT outputs –0.6V(typ) when there is no video signal input.

Note: 17. Low quality video signal has the following characteristics.

Input Sync Tip Level= -0.43V~ -0.14V (from the pedestal voltage)

Horizontal Line Sync Pulse=4.0μs ∼5.4μs, Equalizing Pulse=2.0μs ∼2.7μs, Serration Pulse=4.0μs ∼5.4μs

CVDD1 Charge

Pump

CP1 CN1 CVSS1 CVEE1

1uF

Negative P o wer

K4254

(+) Cb

Ca (+)

Figure 3. Negative Power Supply Circuit

ASAHI KASEI [AK4254]

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VOUT1

75Ω

K4254

75Ω

(VOUT2)

Figure 4. Video Signal Output

■ Serial Interface

The AK4254 can select 3-wire Serial mode (I2C pin = “L”) or I2C Bus mode (I2C pin =“H”).

1.3-wire Serial mode (I2C pin = “L”)

Internal registers may be written by using the 3-wire µP interface pins (CSN, CCLK and CDTI pins). The data on this

interface consists of a 2-bit Chip address (C1 and C2 are set by CAD1, CAD0pin), Read/Write (Fixed to “1”), Register

address (MSB first, 5bits) and Control data (MSB first, 8bits). If the Chip address matches the setting of the CAD1 pin

and CAD0pin, the AK4254 operation is executed. Each bit is clocked in on the rising edge (“↑”) of CCLK. Address and

data are latched on the 16th CCLK rising edge (“↑”) after CSN falling edge (“↓”). CSN should be set to “H” once after 16

CCLKs for each address. Clock speed of CCLK is 5MHz (max). The value of internal registers are initialized by the PDN

pin = “L”.

CDTI

CCLK

CSN

0 1 2 345678 9 10 11 12 13 14 15

D4D5D6D7A1A2A3A4R/WC0 A0 D0 D1 D2 D3

C1,C0: Chip Address: (C1= CAD1, C0 = CAD0)

R/W: READ/WRITE (Fixed to “1”: WRITE)

A4-A0: Register Address

D7-D0: Control Data

Figure 5. 3-wire Serial mode I/F timing

ASAHI KASEI [AK4254]

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2. I2C Bus mode

The AK4254 supports the fast-mode I2C-bus (max: 400kHz).

2-1. WRITE operations

Figure 6 shows the data transfer sequence for the I2C-bus mode. All commands are preceded by a START condition. A

HIGH to LOW transition on the SDA line while SCL is HIGH indicates the START condition (Figure 12). After the

START condition, a slave address is sent. This address is 7 bits long followed by the eighth bit that is a data direction bit

(R/W). The most significant six bits of the slave address are fixed as “00100”. The next bits are CAD0-1 (device address

bit). This bit identifies the specific device on the bus. The hard-wired input pin (CAD0-1 pins) sets these device address

bits(Figure 7). If the slave address matches that of the AK4254, the AK4254 generates an acknowledge and the operation

is executed. The master must generate the acknowledge-related clock pulse and release the SDA line (HIGH) during the

acknowledge clock pulse (Figure 13). A R/W bit value of “1” indicates that the read operation is to be executed. A “0”

indicates that the write operation is to be executed.

The second byte consists of the control register address of the AK4254. The format is MSB first, and those most

significant 7-bits are fixed to zeros (Figure 8). The data after the second byte contains control data. The format is MSB

first, 8bits (Figure 9). The AK4254 generates an acknowledge after each byte has been received. A data transfer is always

terminated by a STOP condition generated by the master. A LOW to HIGH transition on the SDA line while SCL is

HIGH defines a STOP condition (Figure 12).

The AK4254 can perform more than one byte write operation per sequence. After receipt of the third byte the AK4254

generates an acknowledge and awaits the next data. The master can transmit more than one byte instead of terminating the

write cycle after the first data byte is transferred. After receiving each data packet the internal 1-bit address counter is

incremented by one, and the next data is automatically taken into the next address.

The data on the SDA line must remain stable during the HIGH period of the clock. The HIGH or LOW state of the data

line can only change when the clock signal on the SCL line is LOW (Figure 14) except for the START and STOP

conditions.

SDA Slave

Address

R/W= "0"

Sub

Address(n) A

Data(n)

Data(n+1)

Data(n+x)

Figure 6. Data Transfer Sequence at the I2C-Bus Mode

0 0 1 0 0 CAD1 CAD0 R/W

Figure 7. The First Byte (Those CAD1/0 should match with CAD1/0 pins)

0 0 0 0 0 0 0 A0

Figure 8. The Second Byte

D7 D6 D5 D4 D3 D2 D1 D0

Figure 9. Byte Structure after the Second Byte

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2-2. READ Operations

(2)-2. READ Operations

Set the R/W bit = “1” for the READ operation of the AK4254. After transmission of data, the master can read the next

address’s data by generating an acknowledge instead of terminating the write cycle after the receipt of the first data word.

After receiving each data packet the internal 2-bit address counter is incremented by one, and the next data is

automatically taken into the next address. If the address exceeds 01H prior to generating a stop condition, the address

counter will “roll over” to 00H and the previous data will be overwritten.

The AK4254 supports two basic read operations: CURRENT ADDRESS READ and RANDOM ADDRESS READ.

2-2-1. CURRENT ADDRESS READ

The AK4254 contains an internal address counter that maintains the address of the last word accessed, incremented by

one. Therefore, if the last access (either a read or write) were to address n, the next CURRENT READ operation would

access data from the address n+1. After receipt of the slave address with R/W bit set to “1”, the AK4254 generates an

acknowledge, transmits 1-byte of data to the address set by the internal address counter and increments the internal

address counter by 1. If the master does not generate an acknowledge to the data but instead generates a stop condition,

the AK4254 ceases transmission.

SDA Slave

Address

R/W = "1"

Data(n+1)

Data(n+2)

Data(n+x)

Data(n)

Figure 10. CURRENT ADDRESS READ

2-2-2. RANDOM ADDRESS READ

The random read operation allows the master to access any memory location at random. Prior to issuing the slave address

with the R/W bit set to “1”, the master must first perform a “dummy” write operation. The master issues a start request, a

slave address (R/W bit = “0”) and then the register address to read. After the register address is acknowledged, the master

immediately reissues the start request and the slave address with the R/W bit set to “1”. The AK4254 then generates an

acknowledge, 1 byte of data and increments the internal address counter by 1. If the master does not generate an

acknowledge to the data but instead generates a stop condition, the AK4254 ceases transmission.

SDA Slave

Address

R/W = "0"

Data(n)

Data(n+x)

Sub

Address(n) SSlave

Address

R/W = "1"

Data(n+1)

Figure 11. RANDOM ADDRESS READ

ASAHI KASEI [AK4254]

MS0586-E-01 2007/08

- 16 -

SCL

SDA

stop conditionstart condition

Figure 12. START and STOP Conditions

SCL FROM

MASTER

acknowledge

DATA

OUTPUT BY

TRANSMITTER

DATA

OUTPUT BY

RECEIVER

1 98

START

CONDITION

not acknowledge

clock pulse for

acknowledgement

Figure 13. Acknowledge on the I2C-Bus

SCL

SDA

data line

stable;

data valid

change

of data

allowed

Figure 14. Bit Transfer on the I2C-Bus

ASAHI KASEI [AK4254]

MS0586-E-01 2007/08

- 17 -

■ Register Map

Addr Register Name D7 D6 D5 D4 D3 D2 D1 D0

00H Input Selector Control 0 SEL22 SEL21 SEL20 0 SEL12 SEL11 SEL10

01H (Reserved) 0 0 0 0 0 0 0 0

The PDN pin = “L” resets the all registers to their default values.

(Note: 18) “The “0” register should be written “0”, the “1” register should be written “1” data.

(Note: 19) Do not write any data to the register except 00H.

■ Register Definitions

Addr Register Name D7 D6 D5 D4 D3 D2 D1 D0

00H Input Selector Control 0 SEL22 SEL21 SEL20 0 SEL12 SEL11 SEL10

Default 0 0 0 0 0 0 0 0

SEL12-10: Input Selector 1 Control (Table 7)

The default is “000” (VOUT1 output is “GND”).

SEL22-20: Input Selector 2 Control (Table 8)

The default is “000” (VOUT2 output is “GND”).

ASAHI KASEI [AK4254]

MS0586-E-01 2007/08

- 18 -

SYSTEM DESIGN

Figure 15∼Figure 17 show the system connection diagram. An evaluation board (AKD4254) is available in order to allow

an easy study on the layout of a surrounding circuit.

CP1

CN1

CVSS1

CVEE1

VOUT1

VDD

VSS

TEST

P/S 10

VIN1 11

VIN2

VIN3

CP2 29

CN2 28

CVSS2 27

CVEE2 26

VOUT2 25

PDN 24

SEL22 23

SEL21 22

SEL20 21

SEL12 20

SEL11 19

SEL10 18

AK4254

VIN4

VIN5

VIN7

VIN6

CVDD1

1 CVDD2 30

1u +

+ 0.1u 10u

Power Supply 3V

+1u

75 75

DSP or μP

0.1u

Video in

Video out Video out

Figure 15. Typical Connection Diagram (Parallel Control Mode)

CP1

CN1

CVSS1

CVEE1

VOUT1

VDD

VSS

TEST

P/S 10

VIN1 11

VIN2

VIN3

CP2 29

CN2 28

CVSS2 27

CVEE2 26

VOUT2 25

PDN 24

I2C 23

CDTI 22

CCLK 21

CSN 20

CAD1 19

CAD0 18

AK4254

VIN4

VIN5

VIN7

VIN6

CVDD1

1 CVDD2 30

1u +

+ 0.1u 10u

Power Supply 3V

+1u

75 75

DSP or μP

0.1u

Video in

Video out

0.1u

0.1u Video in

Video out

Figure 16. Typical Connection Diagram (Serial Control Mode: 3-wire Serial mode)

ASAHI KASEI [AK4254]

MS0586-E-01 2007/08

- 19 -

CP1

CN1

CVSS1

CVEE1

VOUT1

VDD

VSS

TEST

P/S 10

VIN1 11

VIN2

VIN3

CP2 29

CN2 28

CVSS2 27

CVEE2 26

VOUT2 25

PDN 24

I2C 23

SDA 22

SCL 21

CSN 20

CAD1 19

CAD0 18

AK4254

VIN4

VIN5

VIN7

VIN6

CVDD1

1 CVDD2 30

1u +

+ 0.1u 10u

Power Supply 3V

+1u

75 75

DSP or μP

0.1u

0.1u Video in

Video in

Video out Video out

Figure 17. Typical Connection Diagram (Serial Control Mode: I2C Bus mode)

1. Grounding and Power Supply Decoupling

The AK4254 requires careful attention to power supply and grounding arrangements. AVDD, CVDD1 and CVDD2 are

usually supplied from the system’s analog supply. AVSS, CVSS1 and CVSS2 of the AK4254 should be connected to the

analog ground plane. System analog ground and digital ground should be connected together near to where the supplies

are brought onto the printed circuit board. Decoupling capacitors should be as near to the AK4254 as possible, with the

small value ceramic capacitor being the nearest.

2. Analog Inputs

Usually the input signal is AC coupled using 0.1uF capacitor (Figure 15, Figure 16, Figure 17).

3. The notes for drawing the board

Analog input and output pins should be as short as possible in order to avoid unwanted coupling into the AK4254. The

unused pins should be open.

4. Video Output

The AK4254 are on-chip 2ch video amp for drive 150Ω resistance. The gain of each amp is +6dB (typ) (Figure 1).

ASAHI KASEI [AK4254]

MS0586-E-01 2007/08

- 20 -

PACKAGE

Det ail A

NO TE : Dimension "*" does not include mold flash.

0.22±0.1 0.65

*9.7±0.1 1.5MAX

115

30pin V SO P (Unit: m m )

5.6±0.1

7.6±0.2

0.45±0.2

-0.0 5

+0.10

0.3

0.15

0.12 M

0.08

1.2±0.10

0.10 +0.10

-0.05

ASAHI KASEI [AK4254]

MS0586-E-01 2007/08

- 21 -

MARKING

AKM

K4254VF

XXXBYYYYC

XXXBYYYYC Date code identifier

XXXB: Lot number (X: Digit number, B: Alpha character)

YYYYC: Assembly date (Y: Digit number, C: Alpha character)

REVISION HISTORY

Date (YY/MM/DD) Revision Reason Page Contents

07/02/20 00 First Edition

07/08/10 01 Spec change 6 Interchannel Isolation: typ.50dB Æ typ.65dB

Spec change 7

Switching characteristics

PDN “↑” to CSN “↓”: tPDCS was added

PDN “↑” to SDA “↓” @SCL = “H”: tPDSD was

added

Spec change 8

Timing diagram

WRITE command input timing was changed. (tPDCS

was added)

I2C Bus mode timing1 was added. (tPDSD was

added)

Error correct 18, 19

System design

Figure15, Figure16, Figure17 were revised. (CVSS1

and CVSS2 were connected to GND)

ASAHI KASEI [AK4254]

MS0586-E-01 2007/08

- 22 -

IMPORTANT NOTICE

z These products and their specifications are subject to change without notice.

When you consider any use or application of these products, please make inquiries the sales office of Asahi Kasei

EMD Corporation (AKEMD) or authorized distributors as to current status of the products.

z AKEMD assumes no liability for infringement of any patent, intellectual property, or other rights in the application or

use of any information contained herein.

z Any export of these products, or devices or systems containing them, may require an export license or other official

approval under the law and regulations of the country of export pertaining to customs and tariffs, currency exchange,

or strategic materials.

z AKEMD products are neither intended nor authorized for use as critical componentsNote1) in any safety, life support, or

other hazard related device or systemNote2), and AKEMD assumes no responsibility for such use, except for the use

approved with the express written consent by Representative Director of AKEMD. As used here:

Note1) A critical component is one whose failure to function or perform may reasonably be expected to result,

whether directly or indirectly, in the loss of the safety or effectiveness of the device or system containing it, and

which must therefore meet very high standards of performance and reliability.

Note2) A hazard related device or system is one designed or intended for life support or maintenance of safety or

for applications in medicine, aerospace, nuclear energy, or other fields, in which its failure to function or perform

may reasonably be expected to result in loss of life or in significant injury or damage to person or property.

z It is the responsibility of the buyer or distributor of AKEMD products, who distributes, disposes of, or otherwise

places the product with a third party, to notify such third party in advance of the above content and conditions, and the

buyer or distributor agrees to assume any and all responsibility and liability for and hold AKEMD harmless from any

and all claims arising from the use of said product in the absence of such notification.