TPS62200, TPS62201, TPS62202, TPS62203

TPS62204, TPS62205, TPS62207, TPS62208

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SLVS417F – MARCH 2002 – REVISED JUNE 2015

7 Detailed Description

7.1 Overview

The TPS6220x device is a synchronous step-down converter operating with typically 1-MHz fixed frequency

pulse width modulation (PWM) at moderate to heavy load currents and in power save mode operating with pulse

frequency modulation (PFM) at light load currents.

During PWM operation the converter uses a unique fast response, voltage mode, controller scheme with input

voltage feed forward. This achieves good line and load regulation and allows the use of small ceramic input and

output capacitors. At the beginning of each clock cycle initiated by the clock signal (S), the P-channel MOSFET

switch is turned on, and the inductor current ramps up until the comparator trips and the control logic turns off the

switch. The current limit comparator also turns off the switch in case the current limit of the P-channel switch is

exceeded. Then the N-channel rectifier switch is turned on and the inductor current ramps down. The next cycle

is initiated by the clock signal again turning off the N-channel rectifier and turning on the P-channel switch.

The GM amplifier and input voltage determines the rise time of the Sawtooth generator; therefore any change in

input voltage or output voltage directly controls the duty cycle of the converter. This gives a very good line and

load transient regulation.

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Product Folder Links: TPS62200 TPS62201 TPS62202 TPS62203 TPS62204 TPS62205 TPS62207 TPS62208