DRV103UG4 Datasheet, PDF (10/24 Pages) Burr-Brown (TI) – PWM LOW-SIDE DRIVER (1.5A and 3A) for Solenoids, Coils, Valves, Heaters, and Lamps

The Duty Cycle Adjust pin is internally driven by an
oscillator frequency dependent current source and connects
to the input of a comparator as shown in Figure 8. The
DRV103’s PWM adjustment is inherently monotonic. That
is, a decreased voltage (or resistor value) always produces
an increased duty cycle.
OSC
+V_S
2.75 • I_REF
3.9V
1.3V
+5V
5kΩ
Pull-Up
OK 7
Thermal Shutdown
Over Current
PWM
DRV103
TTL or HCT
5
OUT
4
FIGURE 9. Non-Latching Fault Monitoring Circuit.
R_PWM
FIGURE 8. Simplified Duty Cycle Adjust Input.
STATUS FLAG
The OK Flag (pin 7) provides a fault indication for over-
current and thermal shutdown conditions. During a fault
condition, the Status OK Flag output is driven LOW (pin
voltage typically drops to 0.3V). A pull-up resistor, as
shown in Figure 9, is required to interface with standard
logic. Figure 9 also gives an example of a non-latching fault
monitoring circuit, while Figure 10 provides a latching
version. The OK Flag pin can sink up to 10mA, sufficient
to drive external logic circuitry, a reed relay, or an LED, as
shown in Figure 11, to indicate when a fault has occurred.
In addition, the OK Flag pin can be used to turn off other
DRV103s in a system for chain fault protection.
Over Current Fault
An over-current fault occurs when the PWM peak output
current is greater than approximately 3.75A. The OK flag is
not latched. Since current during PWM mode is switched on
and off, the OK flag output will be modulated with PWM
timing (see OK flag waveforms in the Typical Performance
Curves).
Avoid adding capacitance to pin 6 (Out) as it may cause
momentary current limiting.
Over-Temperature Fault
A thermal fault occurs when the die reaches approximately
160°C, producing a similar effect as pulling the input low.
Internal shutdown circuitry disables the output. The OK
Flag is latched in the LOW state (fault condition) until the
die has cooled to approximately 140°C.
OK
OK
OK Reset
74XX76A
V_S
Q
J
Q
CLR CLK
GND K
+5V
20kΩ
(1)
OK 7
Thermal Shutdown
Over Current
PWM
DRV103
5
OUT
4
NOTE: (1) Small capacitor (10pF) may be required in noisy environments.
FIGURE 10. Latching Fault Monitoring Circuit.
+5V
5kΩ
OK 7
(LED)
HLMP-Q156
Thermal Shutdown
Over Current
PWM
DRV103
5
OUT
4
FIGURE 11. LED to Indicate Fault Condition.
10
DRV103
SBVS029A