JRC NJM3548TA2 Datasheet
UNIVERSAL SOURCE DRIVER
■ GENERAL DESCRIPTION ■ PACKAGE OUTLINE
NJM3548 is a bipolar universal high-current highly protected
high side driver with transparent input and 2000mA continuous
-current source capability. A low-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 VCC.
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.
Typical loads are solenoids, relays or resistive loads.
The NJM3548 and NJM3545 are complementary drivers and
have similar data.
■ FEATURES
NJM3548TA2
NJM3548
• 2000mA continuous-output current
• Short circuit to ground protection
• Error signal to host system
• Open circuit detection
• Short circuit to VCC detection
• Thermal protection
• Built-in protection diodes
• Package TO-220 (5-pin)
■ BLOCK DIAGRAM
NJM3548
Input
Error
To logic
Voltage reference
QRS
Thermal
protection
Short-circuit to
GND protection
h
Short-circuit to
V detection
cc
Open circuit
detection
V
cc
Output
GND
Figure 1. Block Diagram
■ PIN CONFIGURATION
NJM3548
NJM 3548TA2
5
4
3
2
1
Output
Supply
GND
Input
Error
Figure 2. Pin Configuration
■ PIN DESCRIPTION
TO-220 Symbol Description
1 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.
2 Input TTL compatible input. A HIGH input signal turns the output transistor off and a LOW
input turns it on. If the input is left open it will be detected as high level.
3 GND Ground supply.
4 Supply Supply voltage. Nominally 5 V to 40 V.
5 Output Output pin. Current flows out from this pin through the load to GND. Nominal current is 8 mA
to 2 A.
NJM3548
Normal
Operation
Active Output
Error
CC
(min 2 A, max 4.5 A)
Undefined Area
I
OS
Short Circuit Protection
Output
Current
Output Voltage
V
CC
VCC - 0.5 V
VCC - 1.3 V
- 3.0 V
V
CC
- 4.5 V
V
CC
(min 2 mA, max 8 mA)
Open Circuit
I
Short Circuit to V
Undefined Area
Undefined Area
Undefined Area
Overload or Short Circuit to GND Error
OMin
Figure 3. Error state vs. output voltage and output current, active output
(0V≤ VIN ≤ 0.8 V, 5 V < VCC < 40 V and -40°C <+TJ >+100°C)
NJM3548
Output Voltage
100% V
CC
50% V
CC
30% V
CC
Inactive Output
Short Circuit to VCC Error
Undefined AreaUndefined Area
Normal Operation
Figure 4. Error state vs. output
voltage, inactive output (2.0 V ≤ V
≤ VCC, 5 V ≤ VCC ≤ 40 V and -40°C
<TJ <+100°C)
IN
NJM3548
■ FUNCTIONAL DESCRIPTION
The circuit NJM3548 is a high 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 NJM3548 and NJM3545 are complementary drivers with equivalent functions and similar data.
NJM3548 is a source driver and NJM3545 is a sink driver.
Input stage
The output stage is switched on and off according to the status of the input. LOW level activates the output. If the
input is left open, the circuit will accept it as a HIGH 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 VCC the driver will leak a maximum of 8µA. See figure 18.
Protection circuitry
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
= 3.5 A typically at TJ= +25°C, see figure 20.
out
has been detected.
A logic-level change at the input will reset the internal error latch. If the fault still is present at turn-on, the circuit
Supply
I
Ref
2
Input
3
GND
Figure 5. Input stage Figure 6. Output stage
Fault condition Input Output Error How to resume normal operation
LOW=ERROR
HIGH=Normal
4
Output
5
GND
3
Normal 0 LOW 1 ON 1 HIGH ——
1 HIGH 0 OFF 1 HIGH ——
V
Short to V
OUT
V
Short to GND 0 LOW 0 OFF 0 LOW Turn off and on after fault condition is removed.
OUT
Open load 0 LOW 1 ON 0 LOW Attach proper load to output or turn off the driver.
Over temperature 0 LOW 0 OFF 0 LOW Temperature is reduced to approx 120°C, or turn off the driver.
=130 °C 1 HIGH 0 OFF 1 HIGH ——
T
J
Figure 7. Error table
0 LOW 1 ON 0 LOW Remove fault condition.
CC
1 HIGH 0 OFF 0 LOW Remove fault condition.
1 HIGH 0 OFF 1 HIGH ——
1 HIGH 0 OFF 1 HIGH ——
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