NR111E Datasheet, PDF (6/13 Pages) Sanken electric – Light Load High Efficiency

Light Load High Efficiency, 31V, Buck Regulator
NR110E series
Oct/23/2012
Functional Block Diagram
2 _５ IN
VIN
C1
C2
R1
7
３
EN
6
７
ISET
ON/
OFF
ISET
OSC
P.REG
Σ
Current
Sense
Amp
OCP
OCP_REF
Drive
REG
VREF
0.8V
OCP_REF
PWM
LOGIC
FB OVP
UVLO
Compensation
FB
0.8V
Err Amp
TSD
１
GND 4
SS
１
SS 8
C9
D2
（ Option)
1
６
BS
R3
C10
3
L1
VO
４
SW
R5
D1
C4
C5
R4
5
８
FB
R6
Pin Assignments & Functions
Pin Functions
Pin No. Symbol
1
BS
2
IN
3
SW
4
GND
5
FB
6
ISET
7
EN
8
SS
Pin Assignments
Description
High-side Boost input.
BS supplies the drive for High-side Nch-MOSFET switch.
Connect a capacitor and a resistor between SW to BS.
Power input. IN supplies the power to the IC as well as the regulator switches
Power switching output.
SW supplies power to the output.
Connect the LC filter from SW to the output.
Note that a capacitor is required from SW to BS to supply the power the High-side
switch
Ground
Connect the exposed pad to Pin No.4
Feedback input Pin to compare Reference Voltage. The feedback threshold is 0.8V.
To set the output voltage, FB Pin is required to connect between resistive voltage
divider R4 and R6.
Adjust Pin of OCP starting current
OCP starting current can be adjusted by connecting a resistor to ISET Pin.
In the case of using at Maximum Io, ISET Pin is required to connect to GND.
Enable input.
Drive EN Pin high to turn on the regulator, low to turn it off.
Soft-Start control input.
To set the soft-start period, connect to a capacitor between GND.
Rev.1.0
SANKEN ELECTRIC CO., LTD.
6
http://www.sanken-ele.co.jp