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AS1341

Datasheet - A p p l i c a t i o n I n f o r m a t i o n

9.7 Input Capacitor

The input filter capacitor reduces peak currents drawn from the power source and reduces noise and voltage ripple on the input caused by the

(EQ 10)

For most applications, non-tantalum type (ceramic, aluminum, polymer, or OS-CON) are preferred due to their robustness to high in-rush

currents typical of systems with low-impedance battery inputs. Alternatively, connect two (or more) smaller value low-ESR capacitors in parallel

to reduce cost. Choose an input capacitor that exhibits less than +10ºC temperature rise at the RMS input current for optimal circuit life.

9.8 Diode Selection

The current in the D1 (see Figure 22 on page 10) changes abruptly from zero to its peak value each time the LX switch turns off. To avoid

excessive losses, the diode must have a fast turn-on time and a low forward voltage.

Note:

Ensure that the diode peak current rating exceeds the peak current limit set by the current limit (see Setting Current Limit on page 11),

9.9 Stable Operation

A well-designed system and selection of high-quality external components can eliminate excessive noise on pins OUT, FB, or GND, which can

lead to unstable device operation. Instability typically manifests itself as grouped switching pulses with large gaps and excessive low-frequency

output ripple (motorboating) during no-load or light-load conditions.

9.10 Recommended Components

Table 7. Recommended Input Capacitor

C

TC Code

Rated Voltage

Manufacturer

10µF

X7R

25V

Murata www.murata.com

Taiyo Yuden www.t-yuden.com

Kemet www.kemet.com

Panasonic www.panasonic.com

Sanyo www.edc.sanyo.com

Table 8. Recommended Components

Input Voltage

Output Voltage

ILIMIT

Inductor

Output Capacitor

4.5V to 20V

1.25V to 5V

High

MSS6132-103ML

LQH66SN-100M03

LQH55DN-150M03

CDRH6D28NP-150

T520V107M010ATE018

A700V826M006ATE018

T520B107M006ATE040

EEFUD0J101R

10TPB100ML

4.5v to 12V

CDRH5D18NP-4R1

LPS4018-472ML

4.5V to 20V

1.25V to 5V

Low

MSS6132-393ML

CDRH6D28NP-470

LQH66SN-470M03

LQH55DN-470M03

EEFCD0K330R

6TPB47M

T520A336M006ATE070

A700V226M006ATE028

4.5V to 12V

MSS6132-103ML

LPS4018-223ML

CDRH5D18NP-220

6V to 20V

High or Low

See Inductors above

510X107M020ATE040