The TPS43000 is a high-frequency, voltage-mode, synchronous PWM controller that can be used in buck,
boost, SEPIC, or flyback topologies. This highly flexible, full-featured controller is designed to drive a pair of
external MOSFETs (one N-channel and one P-channel), enabling it for use with a wide range of
output voltages and power levels. With an automatic PFM mode, a shutdown current of less than 1 uA, a
sleep-mode current of less than 100 uA and a full operating current of less than 2 mA at 1 MHz, it is ideal
for building highly efficient, dc-to-dc converters.
The TPS43000 operates over a wide input voltage range of 1.8 V to 9.0 V. Typical power sources are
distributed power systems, two to four nickel or alkaline batteries, or one to two lithium-ion cells. It can be used
to generate regulated output voltages from as low as 0.8 V to 8 V or higher. It operates either in a
fixed-frequency mode, where the user programs the frequency (up to 2 MHz), or in an automatic PFM mode.
In the automatic mode, the controller goes to sleep when the inductor current goes discontinuous, and
wakes up when the output voltage has fallen by 2%. In this hysteretic mode of operation, very high efficiency
can be maintained over a very wide range of load current. The device can also be synchronized to an
external clock source using the dual function SYNC/SD input pin.
The TPS43000 features a selectable two-level current-limit circuit which senses the voltage drop across the
energizing MOSFET. The user can select either pulse-by-pulse current limiting or hiccup mode overcurrent
protection. The TPS43000 also features a low-power (LP) mode (which reduces gate charge losses in the
N-channel MOSFET at high input/output voltages), undervoltage lockout, and soft-start. The TPS43000 is
available in a 16-pin TSSOP (PW) package.