L4978 STMicroelectronics, L4978 Datasheet - Page 2

• Manufacturer Part Number: L4978
• Description: IC REG SW 2A STEP DOWN 8-DIP
• Manufacturer: STMicroelectronics
• Type: Step-Down (Buck)r

Specifications of L4978

• Internal Switch(s): Yes
• Synchronous Rectifier: No
• Number Of Outputs: 1
• Voltage - Output: 3.3 ~ 50 V
• Current - Output: 2A
• Frequency - Switching: 100kHz ~ 300kHz
• Voltage - Input: 8 ~ 55 V
• Operating Temperature: -40°C ~ 150°C
• Mounting Type: Through Hole
• Package / Case: 8-DIP (0.300", 7.62mm)
• Power - Output: 1W
• Output Voltage: 50 V
• Output Current: 2 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: Through Hole
• Duty Cycle (max): 97 %
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 497-6701-5; E-L4978; E-L4978; L4978

L4978
Table 2. Block Diagram
Figure 3. Pins Connection (Top view)
Table 3. Pin Description
2/13
N°
1
2
3
SS_INH
SS_INH
COMP
GND
FB
OSC
OUT
Pin
3.3V
2
3
4
2
7
8
SHUTDOWN
INHIBIT
THERMAL
1
2
3
4
OSCILLATOR
SS_INH
E/A
Name
GND
OSC
DIP-8
D97IN595
OSC
3
SOFTSTART
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 disables 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)
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
SO16W
5
VCC
OUT
4
AT LIGHT
CHARGE
CHARGE
CBOOT
CBOOT
16
15
14
13
12
11
10
LOADS
9
D97IN594
6
N.C.
N.C.
FB
COMP
BOOT
VCC
N.C.
N.C.
BOOT