1

C1

2

10 kHz

R1

=

´ p ´

´

out

R1

V

0.5 V

1

R2

æ

ö

=

´

+

ç

÷

è

ø

VI

GND

EN

SW

FB

C3

4.7 mF

L1

10 mH

C4

10 mF

TPS62200

VI

2.5 V − 6 V

VO

1.8 V / 300 mA

R1

470k

R2

180k

C1

33 pF

C2

100 pF

TPS62200, TPS62201, TPS62202, TPS62203

TPS62204, TPS62205, TPS62207, TPS62208

www.ti.com

SLVS417F – MARCH 2002 – REVISED JUNE 2015

8 Application and Implementation

NOTE

Information in the following applications sections is not part of the TI component

specification, and TI does not warrant its accuracy or completeness. TI’s customers are

responsible for determining suitability of components for their purposes. Customers should

validate and test their design implementation to confirm system functionality.

8.1 Application Information

The TPS6220x devices are a family of high-efficiency synchronous step-down converters ideally suited for

portable systems powered by 1-cell Li-Ion or 3-cell NiMH/NiCd batteries. The devices are also suitable to operate

from a standard 3.3-V or 5-V voltage rail.

8.2 Typical Application

Figure 5. Typical Application Circuit for the Adjustable Output Voltage

8.2.1 Design Requirements

The Detailed Design Procedure provides a component selection to operate the device within the Recommended

Operating Conditions.

8.2.2 Detailed Design Procedure

8.2.2.1 Adjustable Output Voltage Version

When the adjustable output voltage version TPS62200 is used, the output voltage is set by the external resistor-

divider. See Figure 5.

The output voltage is calculated as:

where

•

R1 + R2

≤ 1 MΩ and internal reference voltage V(ref)typ = 0.5 V.

(4)

R1 + R2 should not be greater than 1 M

Ω for reasons of stability. To keep the operating quiescent current to a

minimum, the feedback resistor-divider should have high impedance with R1+R2

≤ 1 MΩ. Because of the high

impedance and the low reference voltage of Vref = 0.5 V, the noise on the feedback pin (FB) needs to be

minimized. Using a capacitive divider C1 and C2 across the feedback resistors minimizes the noise at the

feedback without degrading the line or load transient performance.

C1 and C2 should be selected as:

where

•

R1 = upper resistor of voltage divider.

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