®
L4938E/ED
L4938EPD
ADVANCED VOLTAGE REGULATOR
ENABLE AND SENSE INPUTS (EN, SI) PRO-
TECTED AGAINST NEGATIVE TRANSIENTS
DOWN TO -5V
RESET THRESHOLD ADJUSTABLE FROM
3.8 TO 4.7V
EXTREMELY LOW QUIESCENT CURRENT,
65µA (LESS THAN 90µA) IN STANDBY
MODE
OPERATING DC SUPPLY VOLTAGE RANGE
5V - 28V
OPERATING TRANSIENT SUPPLY VOLT-
AGE UP TO 40V
HIGH PRECISION STANDBY OUTPUT VOLT-
AGE 5V
±
1% WITH 100mA CURRENT CA-
PABILITY
OUTPUT 2 VOLTAGE 5V
±
2% WITH 400mA
CURRENT CAPABILITY (ADJ WIRED TO
V
OUT2
)
OUTPUT 2 VOLTAGE ADJUSTABLE BY EX-
TERNAL VOLTAGE DIVIDER
OUTPUT 2 DISABLE FUNCTION FOR
STANDBY MODE
PIN CONNECTIONS
DIP (12+2+2)
SO20 (12+4+4)
PowerSO20
ORDERING NUMBERS:
L4938E (DIP)
L4938ED (SO)
L4938EPD (PSO)
DESCRIPTION
The L4938E/ED/EPD is a monolithic integrated
dual voltage regulator with two very low dropout
outputs and additional functions as power-on re-
set and input voltage sense. It is designed for
supplying the microcomputer controlled systems
especially in automotive applications.
PR
1
2
3
4
5
6
7
8
9
10
D94AT076A
20
19
18
17
16
15
14
13
12
11
SI
VS1
VS2
GND
GND
GND
GND
N.C.
OUT2
ADJ
PR
CT
EN
GND
GND
RES
SO
OUT1
1
2
3
4
5
6
7
8
D94AT075A
16
15
14
13
12
11
10
9
SI
VS1
VS2
GND
GND
N.C.
OUT2
ADJ
GND
N.C.
V
S2
V
S1
SI
PR
CT
EN
N.C.
GND
1
2
3
4
5
6
7
8
9
10
L4938EPD
20
19
18
17
16
15
14
13
12
11
GND
N.C.
OUT2
ADJ
OUT1
SO
RESET
N.C.
N.C.
GND
CT
EN
GND
GND
GND
GND
RES
SO
OUT1
DIP (12+2+2)
SO (12+4+4)
PowerSO20
February 1999
1/12
STMICROELECTRONICS [ STMICROELECTRONICS ]
