TPSM82821 datasheet(7/54 Pages) TI

7 / 54 page

8 Detailed Description

8.1 Overview

The TPSM8282x synchronous step-down converter power module is based on DCS-Control (Direct Control

with Seamless transition into power save mode). This is an advanced regulation topology that combines the

advantages of hysteretic, voltage, and current mode control.

The DCS-Control topology operates in PWM (pulse width modulation) mode for medium to heavy load conditions

and in PSM (power save mode) at light load currents. In PWM, the converter operates with its nominal

switching frequency of 4 MHz, having a controlled frequency variation over the input voltage range. As the load

current decreases, the converter enters power save mode, reducing the switching frequency and minimizing the

quiescent current of the IC to achieve high efficiency over the entire load current range. DCS-Control supports

both operation modes using a single building block and, therefore, has a seamless transition from PWM to PSM

without effects on the output voltage.

The forced PWM versions of this device, the TPSM8282xA, does not enter PSM (power save mode) at light load

currents and stays in CCM (continuous conduction mode) regardless of the output current in order to minimize

the output ripple.

The TPSM8282x offers excellent DC voltage regulation and load transient regulation, combined with low output

voltage ripple, minimizing interference with RF circuits.

8.2 Functional Block Diagram

VOUT

GND

Output Discharge

Logic

Direct Control

and

Compensation

Timer

ton

Comparator

Ramp

Error Amplifier

DCS - Control

MOSFET Driver

Control Logic

High Side

Current Sense

Hiccup

Counter

VIN

Bandgap

Undervoltage Lockout

Thermal Shutdown

REF

(1)

Fixed VOUT

VPGTH(high)

VFB

VPGTH(low)

deglitch

(1) Inductance value is 0.47 µH in TPSM82821/TPSM82821A, 0.24 µH in TPSM82822/TPSM82822A and 0.24 µH in TPSM82823/

TPSM82823A.

8.3 Feature Description

8.3.1 PWM and PSM Operation

The TPSM8282x includes a fixed on-time (tON) circuitry. This tON, in steady-state operation in PWM and PSM

modes, is estimated as:

www.ti.com

TPSM82823, TPSM82822, TPSM82821, TPSM82823A, TPSM82822A, TPSM82821A

SLVSEP0F – AUGUST 2019 – REVISED NOVEMBER 2021

Submit Document Feedback

Product Folder Links: TPSM82823 TPSM82822 TPSM82821 TPSM82823A TPSM82822A TPSM82821A

TPSM82821 Datasheet(PDF) 7 Page - Texas Instruments

TPSM82821 Datasheet(HTML) 7 Page - Texas Instruments

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54

Datasheet Download

Link URL