JRC NJM3545TA2 Datasheet

UNIVERSAL SINK DRIVER

■ GENERAL DESCRIPTION ■ PACKAGE OUTLINE

NJM3545 is a bipolar universal high-current highly protected

low side driver with transparent input and 2000mA continuous

-current sink capability. A high-level input activates the output.
The driver is equipped with extensive electrical protection;

such as over current protection and thermal protection,

which makes the device virtually indestructible.

Furthermore it can detect open circuit and short circuit to ground.

A special feature is the Error indicating output function pin

which signals to the host system if the protection or the load
check functions is activated.

The NJM3545 and NJM3548 are complementary drivers and

have similar data.

■ FEATURES

• 2000mA continuous-output current

NJM3545TA2

NJM3545

• Short circuit to VCC protection

• Error signal to host system

• Open circuit detection

• Short circuit to ground detection

• Thermal protection

• Built-in protection diodes

• Package TO-220 (5-pin)

■ BLOCK DIAGRAM

NJM3545

Input

Error

To logic

Voltage reference

QRS

Open circuit
detection

Supply

Thermal
protection

Short-circuit to
V protection

cc

Short-circuit to
GND detection

Output

Figure 1. Block Diagram

GND

■ PIN CONFIGURATION

NJM3545

NJM3545TA2

5
4
3
2
1

Input
Error
GND
Output
Supply

Figure 2. Pin description

■ PIN DESCRIPTION

TO-220 Symbol Description

1 Supply Supply voltage. Nominally 5 V to 40 V.
2 Output Output pin. Current flows from supply through the load into the pin. Nominal current is 8 mA to 2 A.
3 GND Ground supply.

diode are bonded to a separate pin.

4 Error Error indicating pin. Sinks current to ground if the protection and/or detection circuitry is activated.

Note: the current must be externally limited to 8 mA.

5 Input TTL compatible input. A LOW input signal turns the output transistor off and a HIGH input turns it on.

Output
voltage

V

cc

3.5 V

2.1 V

Open circuit

0.6 V

0.2 V

(min 0.5 mA, max 8 mA)

Undefined area

I

OMIN

Short circuit to GND error

NJM3545

Active output

Overload or short
circuit to V Error

cc

Undefined area

Normal operation

Undefined area

Undefined area

Short circuit protection

I

OS

(min 2 A, max 4.5 A)

Output
current

Figure 3. Error state vs. output voltage and output current, active
output (2.0 ≤ VIN ≤ VCC), 5 V < VCC < 40 V, - 40°C <TJ < +100°C

Output
voltage

NJM3545

Inactive output

100% V

cc

Normal operation

70% V

cc

Undefined area

50% V

cc

Short circuit to GND Error

0% V

cc

Figure 4. Error state vs. output voltage,
inactive output (0 V ≤ VIN ≤ 0.8 V), 5 V ≤
VCC ≤ 40 V, - 40°C < TJ < +100°C

NJM3545

■ FUNCTIONAL DESCRIPTION

The circuit NJM3545 is a low side driver capable of driving resistive or inductive loads not exceeding 2 A.

The driver has an error indicating function which generates an Error output signal when a fault condition has

occurred.

The circuits NJM3545 and NJM3548 are complementary drivers with equivalent functions and similar data.

NJM3545 is a sink driver and NJM3548 is a source driver.

Input stage

The output stage is switched on and off according to the status of the input. HIGH level activates the output. If the
input is left open, the circuit will accept it as a LOW level.

Output stage

The output stage contains a power transistor and two clamping diodes. The diodes are used for terminating line
transients from inductive loads. If the driver is inactive and the output is shorted to GND the driver will leak maxi­mum
8 µA. See figure 18.

Protection circuit

The circuit contains two protection circuits:

• Overload and Short circuit protection

• Thermal protection

The overload and short circuit protection will be activated at I

The output will be turned off immediately and latched to a high-impedance state after an overload or short circuit

has been detected.

= 3.5 A typically at TJ= +25°C, see figure 20.

out

1

Input

I

Ref

5

CC

2

Output

3

GND

3

Figure 6. Output stageFigure 5. Input stage

Fault condition Input Output Error How to resume normal operation

LOW=Error
HIGH=Normal

Normal 0 LOW 1 OFF 1 HIGH ——

1 HIGH 0 ON 1 HIGH ——

V

Short to GND 0 LOW 1 OFF 0 LOW Remove fault condition.

OUT

1 HIGH 0 ON 0 LOW Remove fault condition.

V

Short to V

OUT

Open load 0 LOW 1 OFF 1 HIGH ——

Over temperature 0 LOW 1 OFF 1 HIGH ——

=130 °C 1 HIGH 1 OFF 0 LOW Temperature is reduced to approx 120°C, or turn off the driver.

T

J

Figure 7. Error table

0 LOW 1 OFF 1 HIGH ——

CC

1 HIGH 1 OFF 0 LOW Turn off and on after fault condition is removed.

1 HIGH 0 ON 0 LOW Attach proper load to output or turn off the driver.

GND