cs51412g ON Semiconductor, cs51412g Datasheet - Page 2

• Manufacturer Part Number: cs51412g
• Description: 1.5a, 260 Khz And 520 Khz, Low Voltage Buck Regulators With External Bias Or Synchronization Capability
• Manufacturer: ON Semiconductor

PACKAGE PIN DESCRIPTION
(CS51412/CS51414)
(CS51412/CS51414)
(CS51411/CS51413)
(CS51411/CS51413)
Package Pin #
SOIC-8
BOOST
SHDNB
BOOST
1
2
3
4
5
5
4
6
7
8
-
BIAS
V
V
V
V
SW
SW
IN
IN
1
1
CS51411/3
CS51412/4
(CS51412/CS51414)
(CS51411/CS51413)
9, 11, 12, 14, 15, 18
Package Pin #
DFN18
8
8
2, 3, 4
5, 6, 7
10
10
13
16
17
1
8
8
V
V
GND
SYNC
V
V
GND
SHDNB
C
FB
C
FB
CS51411, CS51412, CS51413, CS51414
BOOST
SHDNB
Pin Symbol
BOOST
SHDNB
SYNC
V
V
Vsw
BIAS
GND
V
V
V
V
V
NC
V
NC
SW
SW
V
SW
FB
IN
IN
IN
IN
C
PIN CONNECTIONS
http://onsemi.com
1
2
3
4
5
6
7
8
9
CS51411/3
The BOOST pin provides additional drive voltage to the on-chip NPN
power transistor. The resulting decrease in switch on voltage increases
efficiency.
This pin is the main power input to the IC.
This is the connection to the emitter of the on-chip NPN power transistor
and serves as the switch output to the inductor. This pin may be
subjected to negative voltages during switch off-time. A catch diode is
required to clamp the pin voltage in normal operation. This node can
stand -1.0 V for less than 50 ns during switch node flyback.
The BIAS pin connects to the on-chip power rail and allows the IC to run
most of its internal circuitry from the regulated output or another low
voltage supply to improve efficiency. The BIAS pin is left floating if this
feature is not used.
This pin provides the synchronization input.
The shutdown pin is active low and TTL compatible. The IC goes into
sleep mode, drawing less than 85 mA when the pin voltage is pulled
below 1.0 V. This pin should be left floating in normal position.
Power return connection for the IC.
The FB pin provides input to the inverting input of the error amplifier. If
V
current limit folds back to about 1 A. These features protect the IC under
severe overcurrent or short circuit conditions.
The V
amplifier and input to the PWM comparator. Driving of this pin should be
avoided because on-chip test circuitry becomes active whenever
current exceeding 0.5 mA is forced into the IC.
No Connection
FB
2
is lower than 0.29 V, the oscillator frequency is divided by four, and
C
pin provides a connection point to the output of the error
18
17
16
15
14
13
12
10
11
NC
V
V
NC
NC
GND
NC
NC
SYNC
C
FB
BOOST
Function
BIAS
V
V
Vsw
V
V
V
NC
SW
SW
IN
IN
IN
1
2
3
4
5
6
7
8
9
CS51412/4
18
17
16
15
14
13
12
10
11
NC
V
V
NC
NC
GND
NC
NC
SHDNB
C
FB