Datasheet

Error
Amplifier
R Q
S
Boot
Charge
Boot
UVLO
UVLO
Current
Sense
Oscillator
Frequency
Shift
Logic
Slope
Compensation
Logic
PWM
Latch
PWM
Comparator
Minimum
Clamp
Pulse
Skip
Maximum
Clamp
Voltage
Reference
Overload
Recovery
SS
COMP
PH
BOOT
VIN
GND
Thermal
Shutdown
EN
Shutdown
Logic
Shutdown
S
Logic
Thermal PAD
Logic
Shutdown
107%
VSENSE
TPS5432DDA Block Diagram
i
1
i
hys
Enable
Comparator
+
_
TPS5432
www.ti.com SLVSB89A –MARCH 2012–REVISED OCTOBER 2012
SIMPLIFIED BLOCK DIAGRAM (DDA)
OVERVIEW
The TPS5432 is a 6-V, 3-A, synchronous step-down (buck) converter with two integrated n-channel MOSFETs.
To improve performance during line and load transients the device implements a constant frequency, peak
current mode control which reduces output capacitance and simplifies external frequency compensation design.
The fixed switching frequency of 700kHz provides the balance between efficiency and size of the output filter
components.
The TPS5432 has a typical default start up voltage of 2.6 V. The EN pin has an internal pull-up current source
that can provide a default condition when the EN pin is floating for the device to operate. The total operating
current for the TPS5432 is typically 360μA when not switching and under no load. When the device is disabled,
the supply current is less than 5μA.
The integrated 70mΩ MOSFETs allow for high efficiency power supply designs with continuous output currents
up to 3 amperes.
The TPS5432 reduces the external component count by integrating the boot recharge diode. The bias voltage for
the integrated high side MOSFET is supplied by a capacitor between the BOOT and PH pins. The boot capacitor
voltage is monitored by an UVLO circuit and turns off the high side MOSFET when the voltage falls below a
preset threshold. The output voltage can be stepped down to as low as the 0.808 V reference.
Copyright © 2012, Texas Instruments Incorporated Submit Documentation Feedback 9
Product Folder Links: TPS5432