L4979D STMicroelectronics, L4979D Datasheet - Page 2

• Manufacturer Part Number: L4979D
• Description: IC VOLTAGE REG LDO SO-8
• Manufacturer: STMicroelectronics
• Type: Step-Down (Buck)r

Specifications of L4979D

• Internal Switch(s): Yes
• Synchronous Rectifier: No
• Number Of Outputs: 1
• Voltage - Output: 5V
• Current - Output: 150mA
• Voltage - Input: 5.6 ~ 31 V
• Operating Temperature: -40°C ~ 150°C
• Mounting Type: Surface Mount
• Package / Case: 8-SOIC (3.9mm Width)
• Polarity: Positive
• Input Voltage Max: 31 V
• Output Voltage: 5 V
• Output Type: Fixed
• Dropout Voltage (max): 0.4 V at 150 mA
• Output Current: 300 mA
• Line Regulation: 25 mV
• Load Regulation: 25 mV
• Voltage Regulation Accuracy: 2 %
• Maximum Operating Temperature: + 150 C
• Mounting Style: SMD/SMT
• Minimum Operating Temperature: - 40 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Power - Output: -
• Frequency - Switching: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

L4979MD L4979D
Table 2. Pin Function
Figure 3. Pins Connection (Top view)
2/10
SO8
N°
1
2
3
4
5
6
7
8
2, 3, 8, 9, 12,
13, 18, 19
5,6,15,16
SO20
N°
10
11
14
17
20
1
4
7
Name
N. C.
Vcw
gnd
gnd
Res
Pin
Vcr
En
Wi
Vo
Vs
GND
GND
GND
VCR
RES
N.C.
N.C.
N.C.
N.C.
EN
Enable input
If high, regulator, watchdog and reset are operating. If low, regulator, watchdog
and reset are shut down.
Ground reference
Ground
These pins are to be connected to a heat spreader electrically grounded
Reset output.
It is pulled down when output voltage drops below Vo_th or frequency at Wi is too
low.
Reset timing adjust
A capacitor between Vcr pin and gnd sets the reset delay time (trd)
Watchdog timer adjust
A capacitor between Vcw pin and gnd sets the time response of the watchdog
monitor.
Watchdog input.
If the frequency at this input pin is too low, the Reset output is activated.
Voltage regulator output
Output capacitor >100nF is needed for regulator stability
Supply voltage
Supply capacitor (e.g. 200nF) is needed for regulator stability.
not connected
GND
VCR
RES
EN
1
2
3
4
5
6
7
8
9
10
1
2
3
4
D00AT457
SO20
SO8
SO8
20
19
18
17
16
15
14
13
12
11
8
7
6
5
Function
V
V
WI
VCW
V
N.C.
N.C.
V
GND
GND
WI
N.C.
N.C.
WCW
S
O
S
O