NJRC NJM3545

NJM3545
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.
NJM3545TA2
■ FEATURES
• 2000mA continuous-output current
• 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
Supply
NJM3545
To logic
Voltage reference
Output
Input
Thermal
protection
Q S
R
Error
Short-circuit to
Vcc protection
Short-circuit to
GND detection
Open circuit
detection
GND
Figure 1. Block Diagram
NJM3545
NJM3545TA2
■ PIN CONFIGURATION
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
3
GND
Ground supply.
4
Error
diode are bonded to a separate pin.
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 pin. Current flows from supply through the load into the pin. Nominal current is 8 mA to 2 A.
Output
voltage
Output
voltage
NJM3545
Active output
Vcc
100% Vcc
Overload or short
circuit to Vcc Error
Normal operation
3.5 V
Undefined area
70% Vcc
Short circuit protection
Normal operation
Undefined area
Open circuit
2.1 V
Undefined area
Undefined area
0.6 V
0.2 V
NJM3545
Inactive output
Undefined area
50% Vcc
Short circuit to GND Error
Short circuit to GND error
IOMIN
I OS
(min 0.5 mA, max 8 mA)
(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
0% Vcc
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 Iout= 3.5 A typically at TJ= +25°C, see figure 20.
The output will be turned off immediately and latched to a high-impedance state after an overload or short circuit
has been detected.
1
I Ref
CC
2
5
Output
Input
GND
3
GND
3
Figure 5. Input stage
Fault condition
Input
Figure 6. Output stage
Output
Error
How to resume normal operation
LOW=Error
HIGH=Normal
Normal
0
LOW
1 OFF
1 HIGH
VOUT Short to GND
1
0
HIGH
LOW
0 ON
1 OFF
1 HIGH
0 LOW
——
Remove fault condition.
VOUT Short to VCC
1
0
HIGH
LOW
0 ON
1 OFF
0 LOW
1 HIGH
Remove fault condition.
——
Open load
1
0
HIGH
LOW
1 OFF
1 OFF
0 LOW
1 HIGH
Turn off and on after fault condition is removed.
——
Over temperature
1
0
HIGH
LOW
0 ON
1 OFF
0 LOW
1 HIGH
Attach proper load to output or turn off the driver.
——
TJ=130 °C
1
HIGH
1 OFF
0
Temperature is reduced to approx 120°C, or turn off the driver.
Figure 7. Error table
LOW
——
NJM3545
A logic-level change at the input will reset the internal error latch. If the fault still is present at turn-on, the circuit
will once again turn the output off.
Due to a slight delay in the circuit, a high current transient will occur when the output is shorted to Vcc. This
current transient may reach 8 A during 5 µs. Consequently, switching at high frequencies with a shorted output
may destroy the circuit. If a short circuit condition is detected, stop switching the input and remove fault condition.
Thermal protection
The output of NJM3545 is equipped with a thermal shut-down function, that turns the outputs off at a chip (junction)
tenperature above typically 130°C.
Normal operation is resumed when the temperature has decreased about 20C.
Error functions
The Error indicating signal occurs on a separate pin. The complete error table is shown in figure 7.
The following conditions generate an error signal:
When the driver is activated and at least one of the following conditions has occurred:
• thermal overload
• short circuit to GND
• short circuit to VCC
• open circuit
An output current less than 8 mA might be detected as “open circuit”. Output currents larger than 8 mA and
less than 2 A will definitely not generate an error. The normal operational area is shown in figure 3.
Also when the driver is inactivated an Error indication can occur. That is if the output is shorted to GND. In figure
4 short circuit to GND Error state versus output voltage is shown.
When the Error-detection function is activated, the Error output is capable of sinking 8 mA, supporting direct
connection of an LED. The current has to be externally limited by a series resistor.
Signal diagrams
The signal diagram in figure 8 shows the input signal and the resulting output signals for each error mode. For
details, see error table, figure 7.
VIN = Input voltage. Active = HIGH.
VOUT = Output voltage.
IOUT = Output current from driver.
VERR = Error output voltage.
Error = LOW.
VIN
VOUT
*
I OUT
VErr
>130° <120°
Normal
operation
Figure 8. Signal diagram
Overload or Short circuit Open circuit Over
short circuit to GND
Undefined temperature
level
*
NJM3545
■ ABSOLUTE MAXIMUM RATINGS
Parameter
Pin no.
Symbol
Voltage
Supply voltage
Logic input voltage
1
5
VCC
VIN
0
-0.3
45
VCC
V
V
Current
Logic input current
Continuous DC Operation output current TO-220
Error output current
5
2
4
IIN
IOUT
IERR
-10
-
2000
10
mA
mA
mA
Temperature
Operating junction temperature (internally limited)
Storage temperature
TJ
TS
-40
+140
+150
°C
°C
Power Dissipation (Package Data)
Power dissipation at TCase = 85°C, TO-220 package
PD
-
11
W
2000
-
V
ESD
ESD tolerance (Note 2)
Min
Max
Unit
■ RECOMMENDED OPERATING CONDITIONS
Parameter
Symbol
Min
Typ
Max
Unit
Supply voltage
VCC
4.75
-
40
Output current TO-220
IOUT
-
-
2000
Operating junction temperature
Tj
-40
-
+100
°C
Error output current
IErr
-
5
8
mA
ON
Supply
voltage
I CC
High
Input level
I OUT I OS
NJM3545
Load
VCC
I OMIN I OL
I IN I IH I IL
Output
90 %
Output voltage
50 %
Input
10 %
t of
+
VIH
VIL
50 %
Low
Supply
VIN
V
mA
I Err
t phl
C1
Fault
Detector
Error
High
GND
Input level
OFF
50 %
Low
VSAT Err
VCE SAT
VCC
VCC
Output voltage
90 %
50 %
10 %
t or
t plh
Figure 9. Definition of symbols
Figure 10. Timing diagram, input vs.
output. VCC = 24V
NJM3545
■ ELECTRICAL CHARACTERISTICS
At 5 V ≤ VCC ≤ 40 V, -40°C ≤ TJ ≤ +100°C. Typical values are given at VCC = 24 V, TJ = 25°C
Parameter
Symbol
General
Supply current
Thermal shutdown
ICC
TJS
Logic input
High level input voltage
Low level input voltage
High level input current
Low level input current
VIH
VIL
IIH
IIH
Outputs
Error output saturation voltage VErr SAT
Output saturation voltage
VCE SAT
Output current shutdown
IOS
Output current
IOMIN
(not detected as open circuit)
Output leakage current
IOL
Clamping diode forward voltage
Timing
Propagation time
Output high to low (50%),
Output low to high (50%),
Rise time (10 to 90%),
Fall time (90 to 10%),
Conditions
Max
Uni
4
+130
7
-
mA
°C
2.0 ≤ VIN ≤ VCC
0 ≤ VIN ≤ 0.8
2.0
-0.3
-400
9
-
VCC
0.8
20
-
V
V
µA
µA
IErr = 5 mA
IOUT = 2 A
2.0 ≤ VIN ≤ VCC
2.0 ≤ VIN ≤ VCC
2.0
0.5
0.2
1.4
3.2
2
1
1.8
4.5
8
V
V
A
mA
0 V≤ VIN ≤0.8 V. Output = 0 V
IF = 2.0 A
-8
-
-6
1.5
-2
1.8
µA
V
-
1.5
0.5
0.2
0.2
3.0
1.0
0.5
0.5
µs
µs
µs
µs
Max
Unit
0 ≤ VIN ≤ 0.8
Min
Typ
1.5
-
IOUT = 2 A
tphl
tplh
tor
tof
■ THERMAL CHARACTERISTICS
Parameter
Thermal resistance
Symbol
Conditions
Min
Typ
Rth j-c
TO-220 package, junction to case
-
5
-
°C/W
Rth J-A
TO-220 package, junction to ambient
-
60
-
°C/W
Notes:
1. Currents are defined positive if flowing into, and negative if flowing out of a terminal. Voltages are defined
between terminal and ground.
2. ESD testing according to Human Body Model (CZap = 100 pF, RZap = 1500 Ω)
NJM3545
■ APPLICATIONS INFORMATION
Important application areas are:
• Programmable logic control systems
• Relay control
• Hydraulic valves
• Intelligent interfaces between microprocessors and loads
• Robot techniques
• Print head drivers
• High-current stepper motor drivers
Transient protection
1. Keep VCC and GND leads as short as possible.
2. Connect a filter capacitor close to the circuit. Recommended filter capacitor between VCC and GND is 6.8 µF, of
tantalum type. A ceramic capacitor in parallel will improve high frequency decoupling. Typical values range from
0.002 µF to 0.1 µF. In an application having a highly stable supply and short power leads to the driver a low
leakage electrolytic type can be used, which is less expensive.
3. Connect Input and Error via pull-up resistors to the appropriate logic supply level or VCC to obtain highest noise
immunity. See figure 11. The resistor R1 limits the current into the Error indicating pin. This current must not exceed
8 mA. R2 is a pull-up resistor which improves noise immunity at the Input. Pull-up current should not exceed the
sinking capacity of the controlling device output.
4. If several supply voltages are to be used, prefere a supply having separate ground leads. In this case the logic
ground and the power ground should be connected together at only one point, the ground pin of the driver.
Switch mode applications
The internal diodes are normally sufficient for clamping of transients caused by inductive load turn off. External
diodes may be necessary in PWM/switch mode applications, and when the terminals are externally accessible and
thereby exposed to an electrically noisy environment. Recommended diodes are BYV27/100,
BYV98/100, UF4001 or similar types with a trr < 100 ns and IF ≥ 1 A.
Error indication signal
When the circuit is switched on/off, a short pulse (tErr <10 µS for resistive loads) is generated at the Error output.
This is a correct detection of an incorrect level during the rise and fall times of the output voltage. Consequently the
Error output should not be detected when switching on and off. An alternative is to low-pass filter at the Error output
at around 100 kHz.
Heat sinking
NJM3545N is packaged in a 5-pin TO 220 power package. The circuit GND is connected to the heat sink tab.
External heatsinking is achieved by mounting the package to a heat sink.
NJM3545
Supply voltage +45 V max.
+5V
R1
Load
Vcc
R 2 5 kΩ
NJM3545
To logic
5
Voltage reference
1
2
Output
Input
TTL,
LS-TTL,
CMOS
Thermal
protection
+
µP,
controller
Q S
R
4
Error
Short-circuit to
Vcc protection
6.8µF
Short-circuit to
GND detection
Open circuit
detection
3
GND
Figure 11. Typical application. Pin numbers refer to TO 220 package
Maximum allowable power dissipation [W]
TO 220 Package
6
5
b
c
4
*
3
a
2
1
0
-40
-20
0
20 40 60 80
Temperature [°C]
100 120 140
a. Ambient temperature. No heatsink. Rth J-A =60°C/W.
b. Mounted on heatsink. Rth J-A =20°C/W @ 4W.
c. Case temperature. Rth J-C =5°C/W.
Figure 12. Maximum allowable power
dissipation. TO 220 package
NJM3545
■ TYPICAL CHARACTERISTICS
I cc (mA)
I F (A)
10
I IN (µ A)
2.0
20
-40°C < T J < 100°C
T J = 25°C
-40°C < T J < 100°C
1.6
16
6
1.2
12
4
0.8
8
2
0.4
4
0
913032
8
0
10
20
30
40
Vcc (V)
50
0
0
0.4
0.8
1.2
1.6
0
2.0
Figure 13. Current consumption vs.
supply voltage at 0 V ≤ Vin ≤ 0.8 V
(Inactive output)
0.5
I OUT (A)
20
5
1.5
2.0
2.5
Figure 15. Input current vs. input
voltage
5 V ≤ VCC ≤ 40 V
I OL (µ A)
-20
T J == 25°C
T J = 25°C
1.0
VIN (V)
Figure 14. Diode forward voltage drop
vs. forward current
I ERR (mA)
4
-16
12
3
-12
8
2
-8
4
1
-4
16
0
VF (V)
-40°C < T J < 100°C
0
0
4
2
6
8
10
0
0.4
0.8
1.2
1.6
2.0
0
2.4
0
10
Figure 16. Error output saturation
voltage vs. error current. VCC = 24 V
PDIS (W)
20
30
VCC (V)
VCE SAT (V)
VERR (V)
Figure 17. Output saturation voltage vs.
output current. 5 V < VCC < 40 V
40
50
Figure 18. Output leakage current vs
supply voltage. 0 V ≤ VIN ≤ 0.8 V
Output = 0 V
I OS (A)
6
5
5
4
4
3
3
2
2
1
0
0.5
1.0
1.5
I OUT (A)
2.0
2.5
3.0
Figure 19. Power dissipation vs. output
current
913042
0
913041
1
0
-40
-20
0
20
40
TJ (°C)
60
80
100
120
Figure 20. Typical output current shut-down vs. chip temperature. 5 V ≤ VCC ≤ 40 V
The specifications on this databook are only
given for information , without any guarantee
as regards either mistakes or omissions. The
application circuits in this databook are
described only to show representative usages
of the product and not intended for the
guarantee or permission of any right including
the industrial rights.