CS8361 - Cherry Semiconductor

Features

VSTBY

Gnd

VIN

–

Current

Limit

Overvoltage

Shutdown

OVSD

TSD

Thermal

Shutdown

Current

Limit

Bandgap

RESET

Adj

–

OVSD

TSD

VIN

–

VSTANDBY

RESET

OVSD

TSD

VTRK

250mA

5V,100mA,2%

ENABLE

RESET

■2 Regulated Outputs

Standby Output 5V

±2%; 100mA

Tracking Output 5V;

250mA

■Low Dropout Voltage

(0.4V at rated current)

■RESET Option

■ENABLE Option

■Low Quiescent Current

■Protection Features

Independent Thermal

Shutdown

Short Circuit

60V Load Dump

Reverse Battery

Package Options

7L TO-220

CS8361

5V Dual Micropower Low Dropout

Regulator with ENABLE and RESET

CS8361

Block Diagram

Description

7L D2PAK

16 Lead PDIP & SOIC Wide

(internally fused leads)

VIN

Gnd

VTRK

Adj

ENABLE RESET

VSTBY

1. VSTBY

2. VIN

3. VTRK

4. Gnd

5. Adj

6. ENABLE

7. RESET

Also available in 20 Lead SOIC Wide.

Consult factory for 20 Lead PSOP .

* Consult factory for positive ENABLE option.

Rev. 5/4/99

The CS8361 is a precision micro-

power dual voltage regulator with

and .

The 5V standby output is accurate

within ±2% while supplying loads

of 100mA and has a typical

dropout voltage of 400mV.

Quiescent current is low, typically

140µA with a 300µA load. The

active output monitors the

5V standby output and holds

the line low during power-

up and regulator dropout condi-

tions. The circuit includes

hysteresis and is guaranteed to

operate correctly with 1V on the

standby output.

The second output tracks the 5V

standby output through an external

adjust lead, and can supply loads

of 250mA with a typical dropout

voltage of 400mV. The logic level

lead is used to control

this tracking regulator output.

Both outputs are protected against

overvoltage, short circuit, reverse

battery and overtemperature condi-

tions. The robustness and low qui-

escent current of the CS8361 makes

it not only well suited for automo-

tive microprocessor applications,

but for any battery powered micro-

processor applications.

ENABLE

RESET

RESETENABLE

Cherry Semiconductor Corporation

2000 South County Trail, East Greenwich, RI 02818

Tel: (401)885-3600 Fax: (401)885-5786

Email: info@cherry-semi.com

Web Site: www.cherry-semi.com

A Company

Electrical Characteristics: 6V ² VIN ² 26V, IOUT1 = IOUT2 = 100µA, -40¡C ² TA ²+125¡C, -40¡C ²TJ² +150¡C,

unless otherwise specified.

PARAMETER TEST CONDITIONS MIN TYP MAX UNIT

CS8361

Absolute Maximum Ratings

Supply Voltage, VIN .....................................................................................................................................................-16V to 26V

Positive Transient Input Voltage, tr > 1ms.............................................................................................................................60V

Negative Transient Input Voltage, T < 100ms, 1% Duty Cycle..........................................................................................-50V

Input Voltage Range ( , ) ...............................................................................................................-0.3V to 10V

Junction Temperature...........................................................................................................................................-40¡C to +150¡C

Storage Temperature Range................................................................................................................................-55¡C to +150¡C

ESD Susceptibility (Human Body Model)..............................................................................................................................2kV

Lead Temperature Soldering

Wave Solder (through hole styles only) .....................................................................................10 sec. max, 260¡C peak

Reflow (SMD styles only) ......................................................................................60 sec. max above 183¡C, 230¡C peak

RESETENABLE

■Tracking Output (VTRK)

VSTBY Ð VTRK, 6V ² VIN ² 26V -25 +25 mV

VTRK Tracking Error 100µA ² ITRK ² 250mA (note 1)

Adjust Pin Current, IAdj Loop in Regulation 1.5 5 µA

Line Regulation 6V ² VIN ² 26V (note 1) 5 50 mV

Load Regulation 100µA ² ITRK ² 250mA (note 1) 5 50 mV

Dropout Voltage (VIN Ð VTRK) ITRK = 100µA 100 150 mV

ITRK = 250mA 400 700 mV

Current Limit VIN = 12V, VTRK = 4.5 275 500 mA

Quiescent Current VIN = 12V, ITRK = 250mA 25 50 mA

No Load on VSTBY

Reverse Current VTRK = 5V, VIN = 0V 200 1500 µA

Ripple Rejection f = 120Hz, ITRK = 250mA 60 70 dB

7V ² VIN ² 17V

■Standby Output (VSTBY)

Output Voltage, VSTBY 6V ² VIN ² 26V 4.90 5.00 5.10 V

100µA ² ISTBY ² 100mA

Line Regulation 6V ² VIN ² 26V 5 50 mV

Load Regulation 100µA ² ISTBY ² 100mA 5 50 mV

Dropout Voltage (VIN Ð VSTBY) ISTBY = 100µA 100 150 mV

ISTBY = 100mA 400 600 mV

Current Limit VIN = 12V, VSTBY = 4.5V 125 200 mA

Short Circuit Current VIN = 12V, VSTBY = 0V 10 100 mA

Quiescent Current VIN = 12V, ISTBY = 100mA 10 20 mA

ITRK = 0mA

VIN = 12V, ISTBY = 300µA 140 200 µA

ITRK = 0mA

Reverse Current VSTBY = 5V, VIN = 0V 100 200 µA

Ripple Rejection f = 120Hz, ISTBY = 100mA 60 70 dB

7V ² VIN ² 17V

Note 1: VTRK connected to Adj lead. VTRK can be set to higher values by using an external resistor divider.

CS8361

Package Lead Description

PACKAGE LEAD # LEAD SYMBOL FUNCTION

Electrical Characteristics: 6V ² VIN ² 26V, IOUT1 = IOUT2 = 100µA, -40¡C ² TA ²+125¡C, -40¡C ²TJ² +150¡C,

unless otherwise specified.

PARAMETER TEST CONDITIONS MIN TYP MAX UNIT

■Functions

Input Threshold 0.8 1.2 2.0 V

Input Bias Current VENABLE = 0V to 10V -10 0 10 µA

Threshold High (VRH)V

STBY Increasing 4.59 4.87 VSTBY-0.02 V

Hysteresis 60 120 180 mV

Threshold Low (VRL)V

STBY Decreasing 4.53 4.75 VSTBY-0.08 V

Leakage 25 µA

Output Voltage

Low (VRLO); RRST = 10k½ 1V ² VSTBY ²V

RL 0.1 0.4 V

Low (VRPEAK)V

STBY, Power Up, Power Down 0.6 1.0 V

■Protection Circuitry (Both Outputs)

Independent Thermal Shutdown VSTBY 150 180 ¡C

VTRK 150 165 ¡C

Overvoltage Shutdown 30 34 38 V

RESET

ENABLE

ENABLERESET

16L PDIP & SO 20L SO Wide

7L 7L Wide (Internally (Internally

TO-220 D2PAK Fused Leads) Fused Leads)

1 1 16 20 VSTBY Standby output voltage delivering 100mA.

22 1 1 V

IN Input voltage.

33 3 2 V

TRK Tracking output voltage controlled by

delivering 250mA.

4 4 4,5,12,13 4,5,6,7 Gnd Reference ground connection.

14,15,16,17

5 5 6 8 Adj Resistor divider from VTRK to Adj. Sets the

output voltage on VTRK. If tied to VTRK, VTRK

will track VSTBY.

66 8 10 Provides on/off control of the tracking output,

active LOW.

7 7 9 11 CMOS compatible output lead that goes low

whenever VSTBY falls out of regulation.

2,7,10, 3,9,12,13, NC No Connection.

11,14,15 18,19

RESET

ENABLE

CS8361

Circuit Description

Application Notes

The function switches the output transistor for

VTRK on and off. When the lead voltage exceeds

1.4V(typ), VTRK turns off. This input has several hundred

millivolts of hysteresis to prevent spurious output activity

during power-up or power-down.

The is an open collector NPN transistor, con-

trolled by a low voltage detection circuit sensing the VSTBY

(5V) output voltage. This circuit guarantees the

output stays below 1V (0.1V typ) when VSTBY is as low as

1V to ensure reliable operation of microprocessor-based

systems.

This output uses the same type of output device as VSTBY,

but is rated for 250mA. The output is configured as a

tracking regulator of the standby output. By using the

standby output as a voltage reference, giving the user an

external programming lead (Adj lead), output voltages

from 5V to 20V are easily realized. The programming is

done with a simple resistor divider (Figure 2), and follow-

ing the formula:

VTRK = VSTBY ´(1 + R1/R2) + IAdj ´R1

If another 5V output is needed, simply connect the Adj

lead to the VTRK output lead.

VTRK Output Voltage

RESET

RESET Function

ENABLE

ENABLE Function

Output capacitors for the CS8361 are required for stability.

Without them, the regulator outputs will oscillate. Actual

size and type may vary depending upon the application

load and temperature range. Capacitor effective series

resistance (ESR) is also a factor in the IC stability. Worst-

case is determined at the minimum ambient temperature

and maximum load expected.

Output capacitors can be increased in size to any desired

value above the minimum. One possible purpose of this

would be to maintain the output voltages during brief

conditions of negative input transients that might be char-

acteristic of a particular system.

Capacitors must also be rated at all ambient temperatures

expected in the system. To maintain regulator stability

down to -40ûC, capacitors rated at that temperature must

be used.

More information on capacitor selection for Smart

Regulatorsª is available in the Smart Regulator applica-

tion note, ÒCompensation for Linear Regulators.Ó

The maximum power dissipation for a dual output regula-

tor (Figure 1) is:

PD(max) = {VIN(max)ÐVOUT1(min)}IOUT1(max)+

{VIN(max)ÐVOUT2(min)}IOUT2(max)+VIN(max)IQ (1)

Where

VIN(max) is the maximum input voltage,

VOUT1(min) is the minimum output voltage from VOUT1,

VOUT2(min) is the minimum output voltage from VOUT2,

IOUT1(max) is the maximum output current, for the

application

IOUT2(max) is the maximum output current, for the

application

IQis the quiescent current the regulator consumes at

IOUT(max).

Once the value of PD(max) is known, the maximum per-

missible value of RQJA can be calculated:

RQJA = (2)

The value of RQJA can then be compared with those in

the package section of the data sheet. Those packages

with RQJA's less than the calculated value in equation 2

will keep the die temperature below 150¡C.

In some cases, none of the packages will be sufficient to

dissipate the heat generated by the IC, and an external

heat sink will be required.

Figure 1: Dual output regulator with key performance parameters

labeled.

VIN

VOUT2

IIN

Control

Features

}

IOUT2

VOUT1

IOUT1

Smart

Regulator

150¡C - TA

Calculating Power Dissipation

in a Dual Output Linear Regulator

External Capacitors

VIN VSTBY

CS8361

Gnd

10µF

ESR<8Ω

VDD

I/O

MCU

Gnd

B+ C2**

C1*

VTRK

RESET

ENABLE

RESET

5V, 100mA

Adj

10µF

ESR<8Ω

C3**

SW 8V,

250mA

* C1 is required if regulator is located far from power supply filter.

** C2 and C3 are required for stability.

VTRK ~ VSTBY (1 + R1/R2)

For VTRK ~ 8V, R1/R2 ~ 0.6

0.1µF

CS8361

Test & Application Circuits

VIN VSTBY

CS8361

Gnd

10µF

ESR<8Ω

VDD

I/O

MCU

Gnd

B+

C2**

C1*

VTRK

RESET

ENABLE

RESET

5V, 100mA

Adj

10µF

ESR<8Ω

C3**

SW 5V,

250mA

0.1µF

* C1 is required if regulator is located far from power supply filter.

** C2 and C3 are required for stability.

A heat sink effectively increases the surface area of the

package to improve the flow of heat away from the IC and

into the surrounding air.

Each material in the heat flow path between the IC and the

outside environment will have a thermal resistance. Like

series electrical resistances, these resistances are summed

to determine the value of RQJA:

RQJA = RQJC + RQCS + RQSA (3)

where:

RQJC = the junctionÐtoÐcase thermal resistance,

RQCS = the caseÐtoÐheat sink thermal resistance, and

RQSA = the heat sinkÐtoÐambient thermal resistance.

RQJC appears in the package section of the data sheet. Like

RQJA, it too is a function of package type. RQCS and RQSA

are functions of the package type, heat sink and the inter-

face between them. These values appear in heat sink data

sheets of heat sink manufacturers.

Heat Sinks

Application Notes: continued

Figure 2: 5V, 8V Regulator

Figure 3: Dual 5V Regulator

Lead Count Metric English

Max Min Max Min

16L PDIP 19.69 18.67 .775 .735

16L SO Wide*10.50 10.10 .413 .398

20L SO Wide* 13.00 12.60 .512 .496

Part Number Description

CS8361YDPS7 7L D2PAK short-leaded

CS8361YDPSR7 7L D2PAK short-leaded, (tape & reel)

CS8361YT7 7L TO-220 (Straight)

CS8361YDWF16 16L SO Wide*

CS8361YDWFR16 16L SO Wide*, (tape & reel)

CS8361YN16 16L PDIP

CS8361YDW20 20L SO Wide*

CS8361YDWR20 20L SO Wide*, (tape & reel)

Ordering Information

CS8361

Cherry Semiconductor Corporation reserves the right to

make changes to the specifications without notice. Please

contact Cherry Semiconductor Corporation for the latest

available information.

Package Specification

PACKAGE DIMENSIONS IN mm(INCHES) PACKAGE THERMAL DATA

Thermal Data typ RQJA RQJC ûC/W

7L D2PAK 10-50** 3.5

7L TO-220 50 3.5

16L PDIP 80 42

16L SO Wide* 75 18

20L SO Wide* 55 9

** Depending on thermal properties of substrate. R

JA = R

JC + R

Plastic DIP (N); 300 mil wide

0.39 (.015)

MIN.

2.54 (.100) BSC

1.77 (.070)

1.14 (.045)

Some 8 and 16 lead

packages may have

1/2 lead at the end

of the package.

All specs are the same.

.203 (.008)

.356 (.014)

REF: JEDEC MS-001

3.68 (.145)

2.92 (.115)

8.26 (.325)

7.62 (.300)

7.11 (.280)

6.10 (.240)

.356 (.014)

.558 (.022)

Surface Mount Wide Body (DW); 300 mil wide

1.27 (.050) BSC

7.60 (.299)

7.40 (.291) 10.65 (.419)

10.00 (.394)

0.32 (.013)

0.23 (.009)

1.27 (.050)

0.40 (.016)

REF: JEDEC MS-013

2.49 (.098)

2.24 (.088)

0.51 (.020)

0.33 (.013)

2.65 (.104)

2.35 (.093)

0.30 (.012)

0.10 (.004)

* Internally Fused Leads

7 Lead D2PAK (DPS)* Short-Leaded

1.98 (.078)

1.47 (.058)

14.71 (.579)

13.69 (.539)

4.57 (.180)

4.31 (.170)

1.40 (.055)

1.14 (.045)

2.79 (.110)

2.54 (.100)

TERMINAL 8

7.75 (.305)

REF

6.50 (.256) REF

10.31 (.406)

10.05 (.396)

1.27 (.050)

REF

1.68 (.066)

1.40 (.055)

.254 (.010)

REF

0.91 (.036)

0.66 (.026)

8.53 (.336)

8.28 (.326)

0.10 (.004)

0.00 (.000)

*CHERRY SEMICONDUCTOR SHORT-LEADED FOOTPRINT

7 Lead TO-220 (T) Straight

2.87 (.113)

2.62 (.103)

9.78 (.385)

10.54 (.415)

1.40 (.055)

1.14 (.045) 0.64 (.025)

0.38 (.015)

0.56 (.022)

0.36 (.014)

1.40 (.055)

1.14 (.045)

4.83 (.190)

4.06 (.160)

14.22 (.560)

13.72 (.540)

0.94 (.037)

0.58 (.023)

7.75 (.305)

7.49 (.295) 2.92 (.115)

2.29 (.090)

3.71 (.146)

3.96 (.156) 14.99 (.590)

14.22 (.560)

6.55 (.258)

5.94 (.234)