Datasheet

max
_ max
2
=
D
+
CS
SENSE
L
ave
V
R
I
I
50
54
58
62
66
70
74
78
0 10 20 30 40 50 60 70 80 90 100
Max Current Sense Threshold (mV)
Duty Cycle (%)
C020
TPS43060
TPS43061
www.ti.com SLVSBP4C –DECEMBER 2012–REVISED SEPTEMBER 2013
Figure 20. OverCurrent Limit Threshold with Respect to Duty Cycle
The maximum current sense threshold V
CSmax
sets the maximum peak inductor current which is the sum of
maximum average inductor (input) current I
ave_max
and half the peak-to-peak inductor ripple ΔI
L
. The sense
resistor value should be chosen based on the desired maximum input current and the ripple current, and can be
calculated using Equation 10.
(10)
GATE DRIVERS
The TPS43060 and TPS43061 contain powerful high-side and low-side gate drivers supplied by the V
CC
bias
regulator. The nominal V
CC
voltage of the TPS43060 and TPS43061 is 7.5 V and 5.5 V respectively. The
TPS43061 gate drivers operate from a 5.5 V V
CC
supply, with drive strength optimized for low Qg NexFETs™. It
also features an integrated bootstrap diode for the high side gate driver to reduce the external part count. The
TPS43060 gate drivers operate from a 7.5 V V
CC
supply, which is suitable to drive a wide range of standard
MOSFETs. The TPS43060 requires an external bootstrap diode from VCC to BOOT to charge the bootstrap
capacitor. It also requires a 2Ω resistor connected in series with the VCC pin to limit the peak current drawn
through the internal circuitry when the external bootstrap diode is conducting. See the ELECTRICAL
CHARACTERISTICS table for typical rise and fall times and the output resistance of the gate drivers.
The LDRV and HDRV outputs are controlled with an adaptive dead-time control that ensures that both the
outputs are never high at the same time. This minimizes any cross conduction and protects the power converter.
The typical dead-time from LDRV fall to HDRV rise is 65 ns.
THERMAL SHUTDOWN
An internal thermal shutdown turns off the TPS43060 and TPS43061 when the junction temperature exceeds the
thermal shutdown threshold (165°C typical). The device will restart when the junction temperature drops by 15°C.
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