ST L4904A User Manual

L4904A

L4904A

DUAL 5V REGULATOR WITH RESET

.OUTPUT CURRENTS : I01 = 50mA

. I02 = 100mA

FIXED PRECISION OUTPUT VOLTAGE

.5V ± 2 %

RESET FUNCTION CONTROLLED BY INPUT

.VOLTAGE AND OUTPUT 1 VOLTAGE

RESET FUNCTION EXTERNALLY PRO-

.GRAMMABLE TIMING

RESET OUTPUT LEVEL RELATED TO

.OUTPUT 2

OUTPUT 2 INTERNALLY SWITCHED WITH

.ACTIVE DISCHARGING

LOW LEAKAGE CURRENT, LESS THAN 1μA

.AT OUTPUT 1

.LOW QUIESCENT CURRENT (Input 1) INPUT OVERVOLTAGE PROTECTION UP TO

.60V

.RESET OUTPUT NORMALLY HIGH

.OUTPUT TRANSISTORS SOA PROTECTION SHORT CIRCUIT AND THERMAL OVERLOAD PROTECTION

DESCRIPTION

The L4904A is a monolithic low drop dual 5V regulator designed mainly for supplying microprocessor systems.

Reset and data save functions during switch on/off can be realized.

Minidip

ORDERING NUMBER : L4904A

PIN CONNECTION

June 2000

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ST L4904A User Manual

L4904A

PIN FUNCTIONS

N°

Name

Function

1Input 1 Low Quiescent Current 50mA Regulator Input.

2Input 2 100mA Regulator Input.

3

Timing

If Reg. 2 is switching-ON the delay capacitor is charged with a

 

Capacitor

Reg. 2 is switched-OFF the delay capacitor is discharged.

4

GND

Common Ground.

5

N.C.

Not connected.

6

Reset

When pin 3 reaches 5V the reset output is switched high.

 

Output

5V

 

 

Therefore tRD = Ct (10μA); tRD (ms) = Ct (nF).

7

Output 2

5V ± 100mA Regulator Output. Enabled if Vo 1 > VRT and VIN 2

 

 

the Co2 capacitor is discharged.

10μA constant current. When

> VIT. If Reg. 2 is switched-OFF

8

Output 1 5V ± 50mA regulator output with low leakage in switch-OFF condition.

BLOCK DIAGRAM

SCHEMATIC DIAGRAM

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L4904A

ABSOLUTE MAXIMUM RATINGS

 

 

 

Symbol

Parameter

 

Value

Unit

VIN

DC Input Voltage

 

24

V

 

Transient Input Overvoltage (t = 40ms)

 

60

V

Io

Output Current

 

Internally Limited

 

Ptot

Power Dissipation at Tamb = 50°C

 

1

W

Tj

Storage and Junction Temperature

 

± 40 to 150

°C

THERMAL DATA

 

 

 

Symbol

Parameter

 

Value

Unit

Rth j-amb

Thermal Resistance Junction-ambient

Max

100

°C/W

ELECTRICAL CHARACTERISTICS (VIN = 14.4V, Tamb = 25oC unless otherwise specified)

Symbol

Parameter

Test Conditions

Vi

DC Operating Input Voltage

 

V01

Output Voltage 1

R Load 1kΩ

V02 H

Output Voltage 2 HIGH

R Load 1kΩ

V02 L

Output Voltage 2 LOW

I02 = ± 5mA

I01

Output Current 1

V01 = ± 100mV

IL01

Leakage Output 1 Current

VIN = 0, V01 3V

I02

Output Current 2

V02 = ± 100mV

VI01

Output 1 Dropout Voltage (*)

I01 = 10mA

 

 

I01 = 50mA

VIT

Input Threshold Voltage

 

VITH

Input Threshold Voltage Hyst.

 

V01

Line Regulation

7V < VIN < 18V, I01 = 5mA

V02

Line Regulation 2

7V < VIN < 18V, I02 = 5mA

V01

Load Regulation 1

VIN = 8V, 5mA < I01 < 50mA

V02

Load Regulation 2

VIN = 8V, 5mA < I02 < 100mA

IQ

Quiescent Current

I02 = I01 5mA

 

 

0 < VIN < 13V

 

 

7V < VIN < 13V

IQ1

Quiescent Current 1

6.3V < VIN1 < 13V, VIN2 = 0

 

 

I01 5mA, I02 = 0

VRT

Reset Threshold Voltage

 

VRTH

Reset Threshold Hysteresis

 

VRH

Reset Output Voltage HIGH

IR = 500μA

VRL

Reset Output Voltage LOW

IR = ± 5mA

tRD

Reset Pulse Delay

Ct = 10nF

td

Timing Capacitor Discharge

Ct = 10nF

 

Time

 

Min.

Typ.

Max.

Unit

 

 

20

V

4.95

5.05

5.15

V

V01 ±0.1

5

V01

V

 

0.1

 

V

50

 

 

mA

 

 

1

μA

100

 

 

mA

 

0.7

0.8

V

 

0.75

0.9

V

V01 + 1.2

6.4

V01 + 1.7

V

 

250

 

mV

 

5

50

mV

 

5

50

mV

 

5

20

mV

 

10

50

mV

 

4.5

6.5

mA

 

 

 

1.6

3.5

 

 

0.6

0.9

mA

V02 ±0.15

4.9

V02 ± 0.05

V

30

50

80

mV

V02 ± 1

4.12

V02

V

 

0.25

0.4

V

3

 

11

ms

 

 

20

μs

V01

Thermal Drift

± 20°C <0>Tamb 125°C

 

0.3

mV/°C

T

 

±0.8

 

 

 

 

V02

Thermal Drift

± 20°C <0>Tamb 125°C

 

0.3

mV/°C

T

 

± 0.8

 

 

 

 

SVR1

Supply Voltage Rejection

f = 100Hz, VR = 0.5V, Io = 50mA

50

84

dB

SVR2

Supply Voltage Rejection

f = 100Hz, VR = 0.5V, Io = 100mA

50

80

dB

* The dropout voltage is defined as the difference between the input and the output voltage when the output voltage is lowered of 25 mV under constant output current condition.

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