L4971D STMicroelectronics, L4971D Datasheet - Page 2

• Manufacturer Part Number: L4971D
• Description: IC REG SW 1.5A STEPDOWN 16-SOIC
• Manufacturer: STMicroelectronics
• Type: Step-Down (Buck)r

Specifications of L4971D

• Internal Switch(s): Yes
• Synchronous Rectifier: No
• Number Of Outputs: 1
• Voltage - Output: 3.3 ~ 50 V
• Current - Output: 1.5A
• Frequency - Switching: 100kHz ~ 300kHz
• Voltage - Input: 8 ~ 55 V
• Operating Temperature: 0°C ~ 125°C
• Mounting Type: Surface Mount
• Package / Case: 16-SOIC (0.300", 7.5mm Width)
• Power - Output: 800mW
• Output Voltage: 50 V
• Output Current: 1.5 A
• Input Voltage: 8 V to 55 V
• Switching Frequency: 90 KHz to 110 KHz
• Operating Temperature Range: - 40 C to + 150 C
• Mounting Style: SMD/SMT
• Duty Cycle (max): 97 %
• For Use With: 497-4744 - BOARD EVAL FOR L4971/L4978 REG
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Other names: 497-1411-5; 497-1411-5; 497-3357-5

L4971
Figure 2. Block Diagram
Figure 3. Pin Connections
Table 2. Pin Description
(*) Pins 1, 7, 8, 9, 10, 15 and 16 are not internally, electrically connected to the die.
2/13
DIP
1
2
3
4
5
6
7
8
SS_INH
COMP
SO (*)
5, 6
11
12
13
14
SS_INH
FB
2
3
4
GND
OSC
OUT
3.3V
2
7
8
SS_INH
COMP
BOOT
Name
GND
OSC
OUT
V
SHUTDOWN
INHIBIT
FB
THERMAL
CC
1
2
3
4
OSCILLATOR
E/A
DIP8
D97IN595
OSC
Ground
A logic signal (active low) disables the device (sleep mode operation).
A capacitor connected between this pin and ground determines the soft start time.
When this pin is grounded disabled the device (driven by open collector/drain).
An external resistor connected between the unregulated input voltage and this pin and
a capacitor connected from this pin to ground fix the switching frequency. (Line feed
forward is automatically obtained)
Stepdown regulator output
Unregulated DC input voltage
A capacitor connected between this pin and OUT allows to drive the internal DMOS
Transistor
E/A output to be used for frequency compensation
Stepdown feedback input. Connecting directly to this pin results in an output voltage of
3.3V. An external resistive divider is required for higher output voltages.
3
SOFTSTART
8
7
6
5
PWM
VOLTAGES
MONITOR
FB
COMP
BOOT
VCC
3.3V
REFERENCE
INTERNAL
R
S
GND
1
Q
SS_INH
GND
OSC
OUT
OUT
N.C.
N.C.
N.C.
INTERNAL
SUPPLY
Function
1
2
3
4
5
6
7
8
DRIVE
5.1V
D97IN596
SO16
5
VCC
OUT
4
16
15
14
13
12
11
10
9
AT LIGHT
CHARGE
CHARGE
CBOOT
CBOOT
LOADS
D97IN594
N.C.
N.C.
FB
COMP
BOOT
VCC
N.C.
N.C.
6
BOOT