iii) C

FIL

A 1 µF, XR7 ceramic capacitor should be connected to pin

C

ternal supply rail of the LM3352.

Of the different capacitor technologies, a sample of vendors

that have been verified as suitable for use with the LM3352

are shown in

Table 2.

TABLE 2. Capacitor Vendor Information

Manufacturer

Tel

Fax

Website

Ceramic

Taiyo-yuden

(408) 573-4150

(408) 573-4159

www.t-yuden.com

AVX

(803) 448-9411

(803) 448-1943

www.avxcorp.com

Tantalum

Sprague/Vishay

(207) 324-4140

(207) 324-7223

www.vishay.com

Nichicon

(847) 843-7500

(847) 843-2798

www.nichicon.com

Polymer Electrolytic

Cornell-Dubilier (ESRD)

(508) 996-8561

(508) 996-3830

www.cornell-dubilier.com

Sanyo (POSCAP)

(619) 661-6322

(619) 661-1055

www.sanyovideo.com

Maximum Available Output Current

The LM3352 cannot provide 200 mA under all V

conditions. The V

mance Characteristics section show the minimum V

which the LM3352 is capable of providing different load cur-

rents while maintaining V

cal Characteristics for guaranteed conditions.

Maximum Load Under Start-Up

Due to the LM3352’s unique start-up sequence, it is not able

to start up under all load conditions. Starting with 45 mA or

less will allow the part to start correctly under any tempera-

ture or input voltage conditions. After the output is in regula-

tion, any load up to the maximum as specified in the Electri-

cal Characteristics may be applied. Using a Power On Reset

circuit, such as the LP3470, is recommended if greater start

up loads are expected. Under certain conditions the LM3352

can start up with greater load currents without the use of a

Power On Reset Circuit (

See application note AN-1144:

Maximizing Startup Loads with the LM3352 Regulated

Buck/Boost Switched Capacitor Converter).

Thermal Protection

During output short circuit conditions, the LM3352 will draw

high currents causing a rise in the junction temperature.

On-chip thermal protection circuitry disables the charge

pump action once the junction temperature exceeds the

thermal trip point, and re-enables the charge pump when the

junction temperature falls back to a safe operating point.

Typical Application Circuits

DS101037-33

FIGURE 2. Basic Buck/Boost Regulator

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