62884CHRTZ View Datasheet(PDF) - Intersil

Part Name

Description

Manufacturer

62884CHRTZ

Single-Phase PWM Regulator for IMVP-6™ Mobile CPUs

Intersil 

ISL62884C

TABLE 1. VID TABLE (Continued)

VO

VID6 VID5 VID4 VID3 VID2 VID1 VID0 (V)

1

0

1

0

1

0

0 0.4500

1

0

1

0

1

0

1 0.4375

1

0

1

0

1

1

0 0.4250

1

0

1

0

1

1

1 0.4125

1

0

1

1

0

0

0 0.4000

1

0

1

1

0

0

1 0.3875

1

0

1

1

0

1

0 0.3750

1

0

1

1

0

1

1 0.3625

1

0

1

1

1

0

0 0.3500

1

0

1

1

1

0

1 0.3375

1

0

1

1

1

1

0 0.3250

1

0

1

1

1

1

1 0.3125

1

1

0

0

0

0

0 0.3000

1

1

0

0

0

0

1 0.2875

1

1

0

0

0

1

0 0.2750

1

1

0

0

0

1

1 0.2625

1

1

0

0

1

0

0 0.2500

1

1

0

0

1

0

1 0.2375

1

1

0

0

1

1

0 0.2250

1

1

0

0

1

1

1 0.2125

1

1

0

1

0

0

0 0.2000

1

1

0

1

0

0

1 0.1875

1

1

0

1

0

1

0 0.1750

1

1

0

1

0

1

1 0.1625

1

1

0

1

1

0

0 0.1500

1

1

0

1

1

0

1 0.1375

1

1

0

1

1

1

0 0.1250

1

1

0

1

1

1

1 0.1125

1

1

1

0

0

0

0 0.1000

1

1

1

0

0

0

1 0.0875

1

1

1

0

0

1

0 0.0750

1

1

1

0

0

1

1 0.0625

1

1

1

0

1

0

0 0.0500

1

1

1

0

1

0

1 0.0375

1

1

1

0

1

1

0 0.0250

1

1

1

0

1

1

1 0.0125

1

1

1

1

0

0

0 0.0000

1

1

1

1

0

0

1 0.0000

1

1

1

1

0

1

0 0.0000

1

1

1

1

0

1

1 0.0000

TABLE 1. VID TABLE (Continued)

VO

VID6 VID5 VID4 VID3 VID2 VID1 VID0 (V)

1

1

1

1

1

0

0 0.0000

1

1

1

1

1

0

1 0.0000

1

1

1

1

1

1

0 0.0000

1

1

1

1

1

1

1 0.0000

COMP

E/A

RDROOP

FB

VDROOP

IDROOP

Σ

DAC

VDAC

INTERNAL TO IC

X1

VCCSENSE

VR LOCAL VO

“CATCH”

RESISTOR

VIDS

VID<0:6>

RTN

VSS

VSSSENSE

“CATCH”

RESISTOR

FIGURE 9. DIFFERENTIAL SENSING AND LOAD LINE

IMPLEMENTATION

As the load current increases from zero, the output

voltage will droop from the VID table value by an amount

proportional to the load current to achieve the load line.

The ISL62884C can sense the inductor current through

the intrinsic DC Resistance (DCR) of the inductors as

shown in Figure 1 or through a resistor in series with the

inductors as shown in Figure 2. In both methods,

capacitor Cn voltage represents the inductor total

currents. A droop amplifier converts Cn voltage into an

internal current source with the gain set by resistor Ri.

The current source is used for load line implementation,

current monitor and overcurrent protection.

Figure 9 shows the load line implementation. The

ISL62884C drives a current source Idroop out of the FB

pin, described by Equation 1.

IDROOP

=

2----x----V----C----n-

Ri

(EQ. 1)

When using inductor DCR current sensing, a single NTC

element is used to compensate the positive temperature

coefficient of the copper winding thus sustaining the load

line accuracy with reduced cost.

Idroop flows through resistor Rdroop and creates a

voltage drop as shown in Equation 2.

VDROOP = RDROOP × IDROOP

(EQ. 2)

VDROOP is the droop voltage required to implement load

line. Changing Rdroop or scaling IDROOP can both change

the load line slope. Since Idroop also sets the overcurrent

protection level, it is recommended to first scale Idroop

based on OCP requirement, then select an appropriate

Rdroop value to obtain the desired load line slope.

14

FN7591.0

March 16, 2010

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