10/24

TSZ02201-0F5F0C100090-1-2

© 2016 ROHM Co., Ltd. All rights reserved.

31.Jan.2016 Rev.001

www.rohm.com

TSZ22111 • 15 • 001

BD92111F

Pin Function Description

PIN.1 VCC

This is power supply pin for the IC. Normal operation range (Typ) is from 9V to 18V. Please place ceramic

capacitor bigger than 0.1µF as bypass capacitor between VCC and GND. It is for noise elimination.

PIN.2 STB

This PIN is for setting of ON/OFF. It is possible to use as reset when shutting down.

Please set the STB terminal voltage below VCC voltage. In addition, please set below 4V if the voltage is applied

earlier than VCC.

Depending on input voltage to STB pin, the status of IC might be switched (ON/OFF). Please avoid using between

the two status (0.8V to 2.0V)

PIN.3 GND

This is signal system GND for IC inside. Please make it independent from PGND as much as possible (We

recommend this because it has less influence with switching noise which comes from short circuit of PGND and

GND at connector close to GND pin.

N1

N2

Vin

GND

GND_PIN

PGND

PIN.4 RT

Set up the charge/discharge current by frequency of IC inside.

By changing the resistance value of resistor between RT pin and GND, it is possible to set up basic drive

frequency as following formula;

Basic frequency means output N1, N2 frequency which is determined only with resistor between RT pin and GND.

]

[

])

[

4

10

5371

.

2

(

)

4

10

4948

.

2

(

])

[

5

10

32

.

3

(

217

.

1

kHz

k

R

k

R

f

RT

RT

OUT



























There is a discrepancy between theoretical formula and actual device. For frequency setting, please thoroughly

verify it with actual application. In addition, frequency may change upon resistor RADJ which is placed between

RT and FB pins

Figure. 11

Figure. 12 RT Resistance vs Output Frequency

1

10

100

1,000

10

100

1000

OSC

RT

BD92111F

FB

IS

VS

Error Amp