L4938ED, L4938EPD Electrical specifications
Doc ID 17243 Rev 2 7/20
2 Electrical specifications
2.1 Absolute maximum ratings
Stressing the device above the ratings listed in the “Absolute maximum ratings” tables may
cause permanent damage to the device. These are stress ratings only and operation of the
device at these or any other conditions above those indicated in the Operating sections of
this specification is not implied. Exposure to the conditions in this section for extended
periods may affect device reliability. Refer also to the STMicroelectronics SURE Program
and other relevant quality documents.
Note: The circuit is ESD protected according to MIL-STD-883C.
Table 3. Absolute maximum ratings
Symbol Parameter Value Unit
V
INDC
DC operating supply voltage 28 V
V
INTR
Transient operating supply voltage (T < 400 ms) -14 to 40 V
I
O
Output current internally limited
V
SI
Sense input voltage (voltage forced)
(1)
1. Current forced means voltage unlimited but current limited to the specified value voltage forced
means voltage limited to the specified values while the current is not limited
-20 to 20 V
I
SI
Sense input current (current forced)
(1)
±1 mA
V
EN
Enable input voltage (voltage forced)
(1)
-20 to 20 V
I
EN
Sense input current (current forced)
(1)
±1 mA
V
RES
, V
SO
Output voltages -0.3 to 20 V
I
RES
, I
SO
Output currents (output low) 5 mA
P
O
Power dissipation at T
amb
=8C
(2)
2. Typical value soldered on a PC board with 8 cm
2
copper ground plane (35 mm thick).
875 mW
T
stg
Storage temperature -65 to 150 °C
T
J
Operating junction temperature -40 to 150 °C
T
JSD
Thermal shutdown junction temperature output 2 will
shutdown typically at T
J
10 K lower than output 1
165 °C
Electrical specifications L4938ED, L4938EPD
8/20 Doc ID 17243 Rev 2
2.2 Thermal data
Note: Typical value soldered on a PC board with 8 cm
2
copper ground plane (35 mm thick).
2.3 Electrical characteristics
V
S
= 14 V; T
j
= -40 to 150 °C, unless otherwise specified.
Table 4. Thermal data
Symbol Parameter SO-20 PowerSO-20 Unit
R
thj-amb
Thermal resistance junction to ambient 50 - °C/W
R
thj-case
Thermal resistance junction to case - < 2 °C/W
Table 5. OUT1
Symbol Parameter Test condition Min. Typ. Max. Unit
V
O1
Supply output voltage
V
S
= 6 to 28 V;
I
O1
= 400 µA to 100 mA
4.9 5 5.1 V
T
J
125°C;
I
O1
= 50 to 400 µA
4.8 5 5.2 V
V
DP1
Drop output voltage 1
I
OUT1
= 10 mA 0.1 0.2 V
I
OUT1
= 100 mA; V
S
= 4.8 V 0.2 0.4 V
V
OL01
Load regulation 1
I
OUT1
= 1 to 100 mA (after
regulation setting)
25 mV
V
LIM1
Current limit 1 V
OUT1
= 0.8 to 4.5 V 100 200 400 mA
I
QSB
Quiescent current in
standby mode
I
EN
2.4 V (output 2 disabled)
I
O1
= 0.1 mA; V
SI
> 1.3 V
65 90 µA
T
J
<8C; R
PR
= 0 75 µA
Table 6. OUT2
Symbol Parameter Test condition Min. Typ. Max. Unit
V
O2
Output voltage 2 ADJ
connected to OUT2
Enable = low; V
S
= 6 to 28 V;
I
O2
= 5 to 400 mA
4.9 5.1 V
V
DP2
Drop output voltage 2
I
OUT2
= 100 mA 0.2 0.3 V
I
OUT2
= 400 mA; V
S
= 4.8 V 0.3 0.6 V
V
OL02
Load regulation 2
I
OUT1
= 5 to 400 mA
(after regulation setting)
50 mV
R
ADJ
Adjust input resistance 60 100 150 mA
I
LIM2
Current limit 2 V
02
= 0.8 to 4.5 V 450 650 1300 mA
I
Q
Quiescent current
I
OUT1
= 100 mA;
I
OUT2
= 400 mA
20 mA
L4938ED, L4938EPD Electrical specifications
Doc ID 17243 Rev 2 9/20
Table 7. OUT1, OUT2
Symbol Parameter Test condition Min. Typ. Max. Unit
V
OLi 1,2
Line regulation
V
S
= 6 to 28 V; I
O1
= 1 mA,
I
O2
= 5 mA,
(after regulation setting)
20 mV
Table 8. Enable input
Symbol Parameter Test condition Min. Typ. Max. Unit
V
ENL
Enable input low voltage
(output 2 active)
-20 1 V
V
ENH
Enable input high voltage 1.4 20 V
V
ENhyst
Enable hysteresis 20 30 60 mV
I
EN LOW
Enable input current low V
EN
= 0 -20 -8 -3 µA
I
EN HIGH
Enable input current high
V
EN
= 1.1 to 7 V;
T
J
< 130 °C;
-1 0 1 µA
V
EN
= 1.1 to 7 V;
T
J
= 130 to 150 °C;
-10 0 10 µA
Table 9. Reset circuit
Symbol Parameter Test condition Min. Typ. Max. Unit
V
RT
Reset threshold voltage
(1)
1. The reset threshold can be programmed continuously from typ 3.8 V to 4.7 V by changing a value of an
external resistor from pin PR to GND.
R
PR
= 4.5
V
O1
-
0.3
V
O1
-
0.2
V
R
PR
= 0 3.65 3.8 3.95 V
V
RTH
Reset threshold hysteresis R
PR
= 30 60 120 mV
t
RD min
Reset pulse delay C
RES
= 47 nF; t
r
30 µs
(2)
2. This is a minimum reset time according to the hysteresis of the comparator. Delay time starts with V
OUT1
exceeding V
RT
.
40 60 100 ms
t
RD nom
Reset pulse delay C
RES
= 47 nF
(3)
3. This is the nominal reset time depending on the discharging limit of C
T
(saturation voltage) and the upper
threshold of the timer comparator. Delay time starts with V
OUT1
exceeding V
RT
.
60 100 140 ms
t
RR
Reset reaction time C
RES
= 47 nF 10 50 150 µs
I
CT
Pull down capability of the
discharge circuit
V
OUT1
< V
RT
3 6 15 mA
I
CT
Charge current V
OUT1
> V
RT
-1.3 -1 0.7 µA
V
RESL
Reset output low voltage
R
RES
= 10 KΩ to V
OUT1
V
OUT1
1.5 V
0.4 V
V
RESH
Reset output high leakage
current
V
RES
= 5 V 1 µA

L4938ED

Mfr. #:
Manufacturer:
STMicroelectronics
Description:
LDO Voltage Regulators Dual 5V Very LDO
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New from this manufacturer.
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