BA12001B / BA12003B / BA12003BF / BA12004B

Standard ICs

Application example

RY

(1) Relay driver

LED

(2) LED driver

Fig.5

Application notes

The BA12001B is a transistor array which can be directly coupled to a general logic circuit such as PMOS, CMOS, or

TTL.

A current limiting resistor needs to be connected in series with the input.

The BA12003B / BF can be coupled directly to TTL or CMOS output (when operating at 5V). In order to limit the input

current to a stable value, resistors are connected in series to each of the inputs.

The BA12004B is designed for direct coupling to CMOS or PMOS output using a 6 to 15V power supply voltage. In order

to limit the input current to a stable value, resistors are connected in series to each of the inputs.

The load for each of these products should be connected between the driver output and the power supply. To protect the

IC from excessive swing voltage, the COM pin (Pin 9) should be connected to the power supply.

Fig.6 shows the configuration of the on-chip diode for surge absorption.

In the construction of the surge-absorbing diode,there is an N-P junction between the N-layer (N-well + BL) and the

substrate (P-sub) so that when the diode is on, current flows from the output pin to the substrate. In terms of the vertical

construction, this diode is configured similar to a PNP transistor. When using the surge-absorbing diode, take appropriate

measures regarding the thermal characteristics of the design considering the current that will be handled.

Also, if motor back-rush current or other conditions that will result continued surge current to flow to the surge-absorbing

diode can be foreseen, we strongly recommend connecting a Schottky barrier diode (or other type of diode with a low

foward voltage) in parallel with the surge-absorbing diode to construct a bypass route for the surge current.

ISO

P

ISO

P

B / L

IDi

Isub

N

+

P

+

In-flow current to the surge-absorbing diode

N

+

N

+

OUT

COM

P-sub

Fig.6 Vertical construction of the surge-absorbing diode

N-well