SC4612HSTRT datasheet(12/21 Pages) SEMTECH

Part #	SC4612HSTRT

Description	40V Synchronous Buck Controller

PDF	21 Pages

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Manufacturer	SEMTECH [Semtech Corporation]

Direct Link	http://www.semtech.com

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SC4612H

POWER MANAGEMENT

The design guidelines are as following:

1. Set the loop gain crossover frequency w

C for given

switching frequency.

2. Place an integrator at the origin to increase DC and low

frequency gains.

3. Select w

Z1 and wZ2 such that they are placed near wO to

dampen peaking; the loop gain should cross 0dB at a rate

of -20dB/dec.

4. Cancel w

ESR with compensation pole wP1 (wP1 = wESR ).

5. Place a high frequency compensation pole w

P2 at half

the switching frequency to get the maximum attenuation

of the switching ripple and the high frequency noise with

adequate phase lag at w

0dB

ESR

Loop gain T(s)

Figure 2. Simplified asymptotic diagram of buck power

stage and its compensated loop gain.

Applications Information (Cont.)

SC4612HSTRT Datasheet(PDF) 12 Page - Semtech Corporation