Cherry Semiconductor CS8141YTVA7, CS8141YTHA7, CS8141YT7, CS8141YN14, CS8141YDWF24 Datasheet

The CS8140 is a 5V Watchdog
Regulator with protection circuitry and
three logic control functions that allow
a microprocessor to control its own
power supply. The CS8140 is designed
for use in automotive, switch mode
power supply post regulator, and bat­tery powered systems.

Basic regulator performance character­istics include a low noise, low drift, 5V
± 4% precision output voltage with low
dropout voltage (1.25V @ I

OUT

= 500mA)

and low quiescent current (7mA @ I

OUT

= 500mA). On board short circuit, ther­mal, and overvoltage protection make it
possible to use this regulator in particu­larly harsh operating environments.

The Watchdog logic function monitors
an input signal (WDI) from the micro­processor or other signal source. When
the signal frequency moves outside
externally programmable window lim­its, a signal is generated
( ). An external capacitor
(C

DELAY

) programs the watchdog win­dow frequency limits as well as the
power on reset (POR) and delay.

The function is activated by any

of three conditions: the watchdog sig­nal moves outside of its preset limits;
the output voltage drops out of regula­tion by more than 4.5%; or the IC is in
its power up sequence. The sig­nal is independent of V

IN

and reliable

down to V

OUT

= 1V.

In conjunction with the Watchdog, the
ENABLE function controls the regula­torÕs power consumption. The CS8140Õs
output stage and its attendant circuitry
are enabled by setting the ENABLE
lead high. The regulator goes into sleep
mode (I

OUT

= 250µA) when the
ENABLE lead goes low and the watch­dog signal moves outside its preset
window limits. This unique combina­tion of control functions in the CS8140
gives the microprocessor control over
its own power down sequence: i.e. it
gives the microprocessor the flexibility
to perform housekeeping functions
before it powers down.

The CS8141 has the same features as the
CS8140, except that the CS8141 only
responds to input signals (WDI) which
are below the preset watchdog frequen­cy threshold.

RESET

RESET

RESET

RESET

RESET

1

Features

■

5V ± 4%, 500mA Output
Voltage

■

µP Compatible Control
Functions

Watchdog

ENABLE

■

Low Dropout Voltage
(1.25V @ 500mA)

■

Low Quiescent Current
(7mA @ 500mA)

■

Low Noise, Low Drift

■

Low Current SLEEP Mode
(I

Q

= 250µA)

■

Fault Protection

Thermal Shutdown

Short Circuit
60V Peak Transient
Voltage

RESET

Package Options

7 Lead TO-220

Tab (Gnd)

14 Lead PDIP

24 Lead SOIC Wide

CS8140/1

5V, 500mA Linear Regulator

with

ENABLE, , and Watchdog

RESET

Delay

V

OUT

Sense

WDI

NC

NC

NC

NC

NC

V

IN

ENABLE

RESET

Gnd

NC

NC

NC

Gnd

NC

NC

NC

NC

NC

NC

NC

CS8140/1

Description

Block Diagram

Delay

V

OUT

Sense

WDI

NC

NC

NC

NC

NC

Gnd

V

IN

ENABLE

RESET

NC

1V

IN

2 ENABLE
3
4 Gnd
5 Delay
6 WDI
7V

OUT

RESET

A Company

¨

Rev. 2/23/99

Cherry Semiconductor Corporation

2000 South County Trail, East Greenwich, RI 02818

Tel: [phone] Fax: [phone]

Email: [e-mail]

Web Site: www.cherry-semi.com

V

IN

Reference

& Bias

Overvoltage

Overtemperature

1

ENABLE

WDI

Gnd

Control Logic

ENABLE

RESET

Delay

Watchdog

Regulation

Short Circuit

Undervoltage

V

OUT

*NOTE: shorted together

*

on 7 Lead TO-220

Sense

RESET

Delay

1

1

2

Electrical Characteristics: 7V ² V

IN

² 26V, 5mA ² I

OUT

² 500mA, -40ûC ² TJ² +150ûC, -40ûC ² TA² 125ûC

unless otherwise specified

PARAMETER TEST CONDITIONS MIN TYP MAX UNIT

Absolute Maximum Ratings

Input Voltage

Operating Range.................................................................................................................................................-0.5 to +26V

Peak Transient Voltage (46V Load Dump @ 14V V

BAT

)..............................................................................................60V

Electrostatic Discharge

(Human Body Model)...............................................................................................................................................4kV

WDI Input Signal Range...............................................................................................................................................-0.3 to +7V

Internal Power Dissipation ..............................................................................................................................Internally limited

Junction Temperature Range (TJ).......................................................................................................................-40¡C to +150¡C

Storage Temperature Range................................................................................................................................-65¡C to +150¡C

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

ENABLE .......................................................................................................................................................................-0.3V to V

IN

CS8140/1

■ Output Stage (V

OUT

)

Output Voltage, V

OUT

7V ² VIN² 26V 4.8 5.0 5.2 V
5mA < I

OUT

< 500mA

Dropout Voltage (VIN- V

OUT

)I

OUT

= 500mA 1.25 1.50 V

Line Regulation I

OUT

= 50mA, 5 25 mV

7V ² VIN² 26V

Load Regulation VIN= 14V, 5 80 mV

50mA ² I

OUT

² 500mA

Output Impedance, R

OUT

500mA DC and 10mA AC , 200 m½

100Hz ² f ² 10kHz

Quiescent Current, (IQ)

Active Mode 0 ² I

OUT

² 500mA, 7V ² VIN² 26V 7.00 15.00 mA

Sleep Mode I

OUT

= 0mA, VIN= 13V, ENABLE = 0V 0.25 0.50 mA

Ripple Rejection 7 ² VIN² 17V, I

OUT

= 250mA, 60 75 dB

f = 120Hz

Current Limit 700 1200 2000 mA
Thermal Shutdown 150 180 ¡C
Overvoltage Shutdown V

OUT

< 1V 30 34 38 V

■ ENABLE

Threshold

HIGH V

OUT

³ 0.5V, (V

OUT(ON)

) 4.05 4.50 V

LOW V

OUT

< 0.5V, (V

OUT(OFF)

) 3.50 3.95 V

Threshold Hysteresis (HIGH - LOW) 100 mV

3

Package Lead Description

Package Lead # Lead Symbol Function

Electrical Characteristics: continued

PARAMETER TEST CONDITIONS MIN TYP MAX UNIT

CS8140/1

■

Threshold

HIGH V

R(HI)

V

OUT

increasing 4.65 4.90 V

OUT

- 0.05 V

LOW V

R(LOW)

V

OUT

decreasing 4.50 4.70 4.90 V

Threshold Hysteresis(V

RH

) (HIGH - LOW) 150 200 250 mV

Reset Output Leakage V

OUT³VR(HI)

25 µA

= HIGH

Output Voltage

Low(V

L(LOW)

) 1V ² V

OUT²VR(LOW)

0.1 0.4 V

Rp = 2.7k½*

Low (V

Rpeak

)V

OUT

, Power up, Power down 0.6 1.0 V

Delay Times C

DELAY

= 0.1µF

t

POR

30.0 47.5 65.0 ms

t

WDI( )

0.5 1.0 1.5 ms

■ Watchdog

Input Voltage

HIGH 2.0 V
LOW 0.8 V

Input Current WDI ² V

OUT

010µA

Threshold Frequency C

DELAY

= 0.1µF

f

WDI

LOWER

64 77 96 Hz

f

WDI(UPPER)**

218 262 326 Hz

* R

P

is connected to and V

OUT

.

** CS8140 only
To observe safe operating junction temperature, low duty cycle pulse testing is used on tests where applicable.

RESET

RESET

RESET

RESET

7 Lead 24 Lead * 14 Lead

TO-220 SOIC Wide PDIP

121 12VINSupply voltage to IC, usually direct from the battery.

2 23 13 ENABLE CMOS compatible logical input. V

OUT

is disabled when

ENABLE is LOW and WDI is beyond its preset limits.

3 24 14 CMOS compatible output lead. goes low whenever

V

OUT

drops below 4.5% of its typical value for more than

2µs or WDI signal falls outside itÕs window limits.

4 12, 20 11 Gnd Ground connection.

5 2 1 Delay Timing capacitor for Watchdog and functions.

6 3 2 WDI CMOS compatible input lead. The Watchdog function mon-

itors the falling edge of the incoming digital pulse train. The
signal is usually generated by the system microprocessor.

74 3V

OUT

Regulated output voltage, 5V (typ).

N/A 5 4 Sense Kelvin connection which allows remote sensing of output

voltage for improved regulation.

1,6-11,13-19,22 5-10 NC No connection.

* The CS8141 uses a fused lead package. Leads 6-8 and 17-19 are fused together through the lead frame. These leads are

electrically connected to IC ground and should be connected to system ground for a good thermal connection.

RESET

RESETRESET

4

Typical Performance Characteristics

CS8140/1

5.5

V

OUT

vs. VINover R

LOAD

; T = 25ûC

V

OUT

vs. VINover Temperature; R

LOAD

= 25½

Dropout Voltage vs. Output Current over Temperature

Load Regulation vs. Output Current over Temperature

Line Regulation vs. Output Current over Temperature

Quiescent Current vs. Output Current over Temperature

(V)

OUT

V

5.0

4.5

4.0

3.5

3.0

2.5

2.0

1.5

1.0

0.5

0.0

V

ENABLE

01 23456 78910

= V

IN

R

load

R

load

= NO LOAD

= 10W

VIN (V)

R

= 6.67W

load

5.5

V

= V

ENABLE

5.0

4.5

4.0

3.5

(V)

3.0

OUT

2.5

V

2.0

1.5

1.0

0.5

0.0

01 23456 78910

IN

TEMP = 125°C

TEMP = -40 °C

TEMP = 25°C

VIN (V)

1800

1600

1400

1200

V

IN

-40°C

25°C

= 14V

125°C

I

25°C

I

OUT

OUT

(mA)

-40°C

125°C

(mA)

1000

800

600

Dropout Voltage (mV)

400

200

0

0 100 200 300 400 500 600 700 800

18

16

14

12

10

8

6

4

2

0

LINE REGULATION (mV)

-2

-4

-6

0 100 200 300 400 500 600 700 800

3.5

0

-3.5

-7.0

-10.5

-14.0

-17.5

-21.0

-24.5

LOAD REGULATION (mV)

-28.0

-31.5

-35.0

10

9

8

7

(mA)

Q

I

6

5

4

0 100 200 300 400 500 600 700 800

25°C

125°C

0 100 200 300 400 500 600 700 800

I

(mA)

OUT

VIN = 14V

-40°C

125°C

25°C

I

(mA)

OUT

V

IN

-40°C

= 14V