PAC5250 datasheet(21/70 Pages) ACTIVE-SEMI

21 / 70 page

PAC5250

Power Application Controller

9V, or 15V by the microcontroller after initialization1. When VP is lower than the target regulation voltage, the internal

feedback control circuitry causes the inductor current to increase to raise VP. Conversely, when VP is higher than the

regulation voltage, the feedback loop control causes the inductor current to decrease to lower VP. The feedback loop is

internally stabilized. The output current capability of the switching supply is determined by the external current sense

resistor. In the high-side current sense buck mode, the inductor current signal is sensed differentially between the CSM pin

and VP, and has a peak current limit threshold of 0.26V. In the low-side current sense flyback or boost mode, the inductor

current signal is sensed differentially between the CSM pin and VSSP, and has a peak current limit threshold of 1V.

The MMSS controller is flexible and configurable as a buck, flyback, or boost converter. Input sources include battery

supply for buck mode (Figure 10-2), and AC line supply voltage range for ultra-high-voltage buck mode (Figure 10-3),

AC/DC flyback mode (Figure 10-4). The MMSS controller operational mode is determined by external configuration and

register setting from the microcontroller after power up. It can operate in either high-side or low-side current sense mode,

and does not require external feedback loop compensation circuitry. For optional extended application range, the MMSS

also incorporates additional digital control by the microcontroller to add accurate computations for outer feedback loop

control such as power factor correction and accurate current control.

Note that on any device with ultra-high voltage drivers (PAC525X), it is invalid to set VP to less than 12V.

- 21 -

Rev 1.6‒January 28, 2016

Figure 10-2. Buck Mode

VHM

DRM

CSM

PAC52xx

(12V default)

VHM

DRM

CSM

PAC5250

Figure 10-3. Ultra-High-Voltage Buck Mode

VHM

DRM

CSM

PAC5250

(12V default)

(120V/230V)

PAC5250 Datasheet(PDF) 21 Page - Active-Semi, Inc