Datasheet
SLVS160C – FEBRUARY 1997 – REVISED OCTOBER 2002
15
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APPLICATION INFORMATION
The on-board series regulator supplies approximately 20 mA of current at 11.5 V, some of which can be used
for external circuitry, providing the power dissipation rating for the driver is not exceeded. When using the
on-board series regulator, an electrolytic output capacitor of 4.7 µF or larger is recommended. Although not
required, a 0.1-µF ceramic capacitor on the input of the regulator can help suppress transient currents (see
Figure 22). When not used, the regulator should be connected to V
CC
. Grounding V
DD
will result in destruction
of the regulator.
Regulator
1
2
3
5
4
34 VDC
TPS2816
0.1 µF
PWM
Controller
0.1 µF
4.7 µF
V
CC
Out
GND
0.1 µF
10 µF
V
O
+
Figure 22. Boost Application
The TPS2816 and TPS2818 drivers include active pullup circuits on the inputs to eliminate the need for external
pullup resistors when using controllers with open-collector outputs (such as the TL5001). The TPS2817 and
TPS2819 drivers have standard CMOS inputs providing a total device operating current of less than 50 µA. All
devices switch at standard CMOS logic levels of approximately 2/3 V
CC
with positive-going input levels, and
approximately 1/3 V
CC
with negative-going input levels. Being CMOS drivers, these devices will draw relatively
large amounts of current (Approximately 5 mA) when the inputs are in the range of one-half of the supply voltage.
In normal operation, the driver input is in this range for a very short time. Care should be taken to avoid use of
very low slew-rate inputs, used under normal operating conditions. Although not destructive to the device, slew
rates slower than 0.1 V/µs are not recommended.
The BiCMOS output stage provides high instantaneous drive current to rapidly toggle the power switch, and
very low drop to each rail to ensure proper operation at voltage extremes.
Low-voltage circuits (less than 14 V) that require very low quiescent currents can use the TPS2828 and
TPS2829 drivers. These drivers use typically 0.2 µA of quiescent current (with inputs high or low). They do not
have the internal regulator or the active pullup circuit, but all other specifications are the same as for the rest
of the family.
2.5-V/3.3-V, 3-A application
Figure 23 illustrates the use of the TPS2817 with a TL5001 PWM controller and a TPS1110 in a simple
step-down converter application. The converter operates at 275 kHz and delivers either 2.5 V or 3.3 V
(determined by the value of R6) at 3 A (5 A peak) from a 5-V supply. The bill of materials is provided in
Table 1.