ST L4901A User Manual

查询L4901供应商



DUAL5V REGULATOR WITH RESET

.

OUTPUTCURRENTS : I01=400mA

I

=400mA

02

.

FIXEDPRECISIONOUTPUTVOLTAGE
5V±2%

.

RESETFUNCTION CONTROLLED BY INPUT
VOLTAGEAND OUTPUT1 VOLTAGE

.

RESET FUNCTION EXTERNALLY PRO­GRAMMABLETIMING

.

RESET OUTPUT LEVEL RELATED TO OUT­PUT 2

.

OUTPUT 2 INTERNALLY SWITCHED WITH
ACTIVEDISCHARGING

.

LOW LEAKAGE CURRENT, LESS THAN 1µA
ATOUTPUT 1

.

LOWQUIESCENTCURRENT (Input 1)

.

INPUT OVERVOLTAGE PROTECTION UP TO
60V

.

RESETOUTPUT HIGH

.

OUTPUTTRANSISTORSSO A PROTECTION

.

SHORT CIRCUIT AND THERMAL OVER­LOADPROTECTION

L4901A

HEPTAWATT (Vertical)

(PlasticPackage)

ORDERING NUMBER : L4901A

DESCRIPTION

The L4901A is a monolithic low drop dual 5V
regulatordesignedmainlyfor supplyingmicroproc­essorsystems.

Resetand data savefunctionsduring switchon/off
canbe realized.

PIN CONNECTION

June 2000

1/10

L4901A

PIN DESCRIPTION

N°

1 Input 1 Low QuiescentCurrent 400mA Regulator Input.
2 Input 2 400mA regulator input.
3 Timing

4 GND Common Ground.
5 Reset

6 Output 2 5V – 400mA Regulator Output. Enabled if V
7 Output 1 5V – 400mA regulatoroutput with Low leakage (in switch-OFF condition).

BLOCKDIAGRAM

Name Function

If Reg. 2 is switched-ON the delay capacitor is charged with a 10µA constant current. When Reg.

Capacitor

2 is switched-OFF the delay capacitor is decharged.

When pin 3 reaches 5V the reset outputis switched high.

Output

Therefore t

the C

RD=Ct

capacitor is discharged.

02

5V

(

); tRD(ms) = Ct(nF)

10µA

1>VRTand V

o

IN 2>VIT

. If Reg. 2 is switched-OFF

SCHEMATIC DIAGRAM

2/10

L4901A

ABSOLUTE MAXIMUMRATINGS

Symbol Parameter Value Unit

V

IN

I

o

T

DC Input Voltage
Transient Input Overvoltage (t = 40ms)

Output Current Internally Limited
Storage and Junction Temperature – 40 to 150

j

THERMAL DATA

Symbol Parameter Value Unit

R

th (j-c)

Thermal Resistance Junction-case Max. 4

24
60

V
V

°C

°C/W

ELECTRICAL CHARACTERISTICS (VIN= 14, 4V, T

=25°C unless otherwise specified)

amb

Symbol Parameter Test Conditions Min. Typ. Max. Unit

DC Operating Input Voltage 20 V

V

i

V

V

V

I

I

L01

I

V

V

V

∆V
∆V
∆V
∆V

I

V

V

V

V

t

∆V

∆

∆V

∆T

SVR1 Supply Voltage Rejection f = 100Hz, V
SVR2 Supply Voltage Rejection 50 80 dB

* The dropoutvoltage is defined as thedifference between theinput and the outputvoltage when theoutput voltage is lowered of 25 mV under
constant output current condition.

Output Voltage 1

01

Output Voltage 2 HIGH

02 H

Output Voltage 2 LOW I02= – 5mA 0.1 V

02 L

Output Current 1

01

Leakage Output 1 Current
Output Current 2 ∆

02

Output 1 Dropout Voltage (*) I01= 10mA

I01

Input Threshold Voltage V01+ 1.2 6.4 V01+ 1.7 V

IT

Input Threshold Voltage Hyst. 250 mV

ITH

Line Regulation 1 7V < VIN< 18V, I01= 5mA 5 50 mV

01

Line Regulation 2 7V < VIN< 18V, I02= 5mA 5 50 mV

02

Load Regulation 1 5mA < I01< 400mA 50 100 mV

01

Load Regulation 2 5mA < I01< 400mA 50 100 mV

02

Quiescent Current

I

Q

Quiescent Current 1

Q1

Reset Threshold Voltage V02– 0.15 4.9 V02–0.05 V

RT

Reset Threshold Hysteresis 30 50 80 mV

RTH

Reset Output Voltage HIGH

RH

Reset Output Voltage LOW IR= –<0>5mA 0.25 0.4 V

RL

Reset Pulse Delay Ct= 10nF 3 5 11 ms

RD

Timing Capacitor Discharge Time Ct= 10nF 20

t

d

01

Thermal Drift

T

02

Thermal Drift

R Load 1kΩ
R Load 1k

= – 100mV

V

∆

01

=0,V01≤ 3V

V

IN

= – 100mV

V

02

= 100mA

I

01

= 300mA

I

01

02=I01

0<V
7V < V

5mA, I

≤

01

= 500µA

R

≤ 5mA

IN

IN

I

I

6.3V < V

I

–20°C≤T

–20°C≤T

Io = 100mA

Ω

< 13V

< 13V

IN

02

< 13V

amb

amb

R

=0,V

≤ 125°C

≤ 125°C

= 0.5V

IN2

=0

4.95 5.05 5.15 V

V01–0.1 5 V

01

400 mA

1

400 mA

0.7

0.8

1.1

4.5

1.6

0.8
1

1.4

6.5

3.5

0.6 0.9 mA

V

– 1 4.12 V

02

02

0.3 –

0.8

0.3 –

0.8

50 84 dB

V

µA

V
V
V

mA

V

µs

mV/°C

mV/°C

3/10