描述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.特性 High-Frequency (2-MHz) Voltage Mode PWM Controller 1.8-V to 9.0-V Input Voltage Range 0.8-V to 8.0-V Output Voltage Range (Higher in Non-Synchronous Boost Topology) High-Efficiency Buck, Boost, SEPIC or Flyback (Buck-Boost) Topology Synchronous Rectification for High-Efficiency Drives External MOSFETs for High-Current Applications Synchronizable Fixed-Frequency PWM or Automatic Pulsed Frequency Modulation (PFM) Mode Built-In Soft-Start User Programmable Discontinuous or Continuous Conduction Mode Selectable Pulse-by-Pulse Current Limiting or Hiccup Mode Protection APPLICATIONS Networking Equipment Servers Base Stations Cellular Telephones Satellite Telephones GPS Devices Digital Still and Handheld Cameras Personal Digital Assistants (PDAs)