HIP6005BCVT - Intersil Corporation

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TB356

Selecting Among HIP6004/5, HIP6004A/5A,

HIP6004B/5B, and HIP6014/15

Introduction

All eight part numbers listed above belong to voltage-mode

PWM controllers targeted at desktop computer and/or

microprocessor applications. These components were

designed with emphasis on various Intel and industry

requirements, speciﬁcally regarding the Pentium II processor

and its derivatives.

Background Details

The e volution of these different, yet very similar ICs, was

dictated by changes in Intel requirements as well as customer

f eedback. To ease the system migration to subsequent parts,

all the ICs are compatible within their class type . Specifically,

all e ven part numbers (HIP6004/4A/4B/14) represent pin-f or-

pin compatible synchronous buck controllers, while the odd

numbers (HIP6005/5A/5B/15) are pin-for-pin compatible

standard buck controllers [1-8]. Among the four pairs (4/5,

4A/5A, 4B/5B, and 14/15), ho w ev er, there are functional

subtleties that diff erentiate them.

Functional Differences

Reference Voltage DAC

All these converters have a 5-bit DAC-controlled internal

voltage reference.

HIP6004 and HIP6005 have an analog DAC, where the VID

inputs connect directly to a resistive internal network.

Shorting various VID (voltage identiﬁcation) inputs to ground

changes the reference voltage and the converter’s output

voltage as a result. The drawback of such architecture is that

the VID inputs have to be either open or shorted to ground.

Pull-up or pull-down resistors on the VID input lines result in

erroneous output voltage settings.

HIP6004A/4B/5A/5B/14/15, on the other hand, have fully

buffered TTL-compatible VID inputs. Pull-ups to 5V do not

affect the output voltage settings (open circuit still regarded

as logic ‘high’). Table 1 summarizes this difference.

Output Voltage Program

Among the eight part types, there are small differences in

the operation of the DAC, as shown in Table 2. While the

DAC is, in all cases, programmed to provide the same output

voltage for a given VID combination, some controllers have

certain voltage settings disabled.

TABLE 1. REFERENCE VOLTAGE DAC TYPE / PULL-UP

COMPATIBILITY

5-BIT DAC 6004/5 6004A/5A 6004B/05B 6014/15

TTL-Compatible No Yes Yes Yes

Pull-up Resistors Not Allowed Allowed Allowed Allowed

TABLE 2. OUTPUT VOLTAGE PROGRAM AND PGOOD

RESPONSE

VID

PINS

LOGIC

STATE OUTPUT VOLTAGE

(HIP60xx) PGOOD LOGIC STATE

(HIP60xx)

VID

4 3 2 1 0 04

05 04A

05A 04B

05B 14

15 04

05 04A

05A 04B

05B 14

0 1 1 1 1 1.30 0 1.30 0 X 0 X 1

0 1 1 1 0 1.35 0 1.35 0 X 0 X 1

0 1 1 0 1 1.40 0 1.40 0 X 0 X 1

0 1 1 0 0 1.45 0 1.45 0 X 0 X 1

0 1 0 1 1 1.50 0 1.50 0 X 0 X 1

0 1 0 1 0 1.55 0 1.55 0 X 0 X 1

0 1 0 0 1 1.60 0 1.60 0 X 0 X 1

0 1 0 0 0 1.65 0 1.65 0 X 0 X 1

0 0 1 1 1 1.70 0 1.70 0 X 0 X 1

0 0 1 1 0 1.75 0 1.75 0 X 0 X 1

0 0 1 0 1 1.80 1.80 1.80 1.80 X X X X

0 0 1 0 0 1.85 1.85 1.85 1.85 X X X X

0 0 0 1 1 1.90 1.90 1.90 1.90 X X X X

0 0 0 1 0 1.95 1.95 1.95 1.95 X X X X

0 0 0 0 1 2.00 2.00 2.00 2.00 X X X X

0 0 0 0 0 2.05 2.05 2.05 2.05 X X X X

1 1 1 1 1 2.00 0 0 0 X 0 1 1

1 1 1 1 0 2.10 2.10 2.10 2.10 X X X X

1 1 1 0 1 2.20 2.20 2.20 2.20 X X X X

1 1 1 0 0 2.30 2.30 2.30 2.30 X X X X

1 1 0 1 1 2.40 2.40 2.40 2.40 X X X X

1 1 0 1 0 2.50 2.50 2.50 2.50 X X X X

1 1 0 0 1 2.60 2.60 2.60 2.60 X X X X

1 1 0 0 0 2.70 2.70 2.70 2.70 X X X X

1 0 1 1 1 2.80 2.80 2.80 2.80 X X X X

1 0 1 1 0 2.90 2.90 2.90 2.90 X X X X

1 0 1 0 1 3.00 3.00 3.00 3.00 X X X X

1 0 1 0 0 3.10 3.10 3.10 3.10 X X X X

1 0 0 1 1 3.20 3.20 3.20 3.20 X X X X

1 0 0 1 0 3.30 3.30 3.30 3.30 X X X X

1 0 0 0 1 3.40 3.40 3.40 3.40 X X X X

1 0 0 0 0 3.50 3.50 3.50 3.50 X X X X

NOTE: ‘X’ = ‘0’ or ‘1’, depending whether the output voltage is within

PGOOD limits

Technical Brief July 1998

Author: Bogdan M. Duduman

Pentium® is a registered trademark of Intel Corporation.

125

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PGOOD Response

During normal converter operation (with the VID

combination resulting in an output voltage other than 0V),

PGOOD asserts a logic ‘high’ (‘1’) if the output voltage is

within 10% (typical) of the DAC setting (reference).

In the case of HIP6004A/5A, for VID settings resulting in

converter shutdown (0V output voltage), PGOOD will assert

a logic ‘low’ (‘0’), thus indicating the absence of output

voltage.

A case that requires special consideration is the dual-

processor system. For these systems, designers use one

converter for each processor, “wire AND-ing” the open-drain

PGOOD signals from both power converters in order to

generate a ‘System Power Good’ signal. However, if these

systems ship with only one processor populated (second

processor offered as an upgrade), the empty processor slot

would generate a ‘11111’ VID code, which in turn would

disable the corresponding converter. If this converter were to

employ a HIP6004A or HIP6005A, the 0V output voltage

setting would generate a PGOOD ‘low’, and consequently

cause the System Power Good to go ‘low’, disabling the

entire computer system. HIP6004B/5B/14/15 handle this

situation by generating a PGOOD ‘high’ for all VID settings

that result in a 0V converter output.

References

For Intersil documents available on the internet, see web site

http://www.intersil.com/

Intersil AnswerFAX (407) 724-7800

[1]

HIP6004 Data Sheet,