Motorola MC33470DW Datasheet

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The MC33470 is a digitally programmable switching voltage regulator, specifically designed for Microprocessor supply, Voltage Regulator Module and general purpose applications, to provide a high power regulated output voltage using a minimum of external parts. A 5–bit digital–to–analog converter defines the dc output voltage.

This product has three additional features. The first is a pair of high speed comparators which monitor the output voltage and expedite the circuit response to load current changes. The second feature is a soft start circuit which establishes a controlled response when input power is applied and when recovering from external circuit fault conditions. The third feature is two output drivers which provide synchronous rectification for optimum efficiency.

This product is ideally suited for computer, consumer, and industrial equipment where accuracy, efficiency and optimum regulation performance is desirable.

MC33470 Features:

• 5–Bit Digital–to–Analog Converter Allows Digital Control of

Output Voltage

• High Speed Response to Transient Load Conditions

• Output Enable Pin Provides On/Off Control

• Programmable Soft Start Control

• High Current Output Drives for Synchronous Rectification

• Internally Trimmed Reference with Low Temperature Coefficient

• Programmable Overcurrent Protection

• Overvoltage Fault Indication

• Functionally Similar to the L TC1553

SYNCHRONOUS

RECTIFICATION DC/DC

CONVERTER

PROGRAMMABLE

INTEGRATED CONTROLLER

SEMICONDUCTOR

TECHNICAL DATA

20

1

DW SUFFIX

PLASTIC PACKAGE

CASE 751D

(SO–20L)

PIN CONNECTIONS

G2

P

V

CC

P

Gnd

A

Gnd

V

CC

Sense

I

max

I

fb

SS

Compensation

1 2 3 4 5 6 7 8 9

10

20 19 18 17 16 15 14 13 12

11

G1 OUTEN VID0 VID1 VID2 VID3 VID4 P

wrgd

Fault OT

This document contains information on a new product. Specifications and information herein are subject to change without notice.

MOTOROLA ANALOG IC DEVICE DATA

(Top View)

ORDERING INFORMATION

Operating

Device

MC33470DW SO–20LTA = 0° to +75°C

 Motorola, Inc. 1997 Rev 0

Temperature Range

Package

1

Voltage

Á

Identification

Code Input

Sense

Power

Good

MC33470

Simplified Block Diagram

18

VID0

17

VID1

16

VID2

15

VID3

14

VID4

V

CC

10

9

SS

6

20 µA

13

Digitally Programmed

Reference

Oscillator

µ

A

0.96 V

ref

V

ref

800

µ

OTA Error Amp

1.5 V

+

PWM

Comparator

1.04 V

ref

1.04 V

ref

0.93 V

ref

2.5 V

Over

Temp

V

ref

1.14 V

OT

ref

11

90

Outen

Over Current

µ

A

S

R

PWM Latch

5

V

19

CC

V

CC

7

Detect

En

Q Q

190 µA

Delay

I 2

P 20 G1

8 I 1 G2

3 P

R

Delay Fault

S

14

Q

max

V

CC

fb

Gnd

Compensation

MAXIMUM RATINGS (T

A

410

Gnd

= 25°C, unless otherwise noted.)

C

Rating Symbol Value Unit

Power Supply Voltage Output Driver Supply Voltage (Operating)

ББББББББББББ

I

, Ifb Inputs

max

All Other Inputs and Digital

V

CC

P

V

ÁÁ

CC

V

in

V

in

ÁÁÁ

–0.3 to 18

–0.3 to

(OT, Fault, Power Good) Outputs VCC + 0.3

Power Dissipation and Thermal Characteristics

Maximum Power Dissipation

Case 751D DW Suffix (TA = 70°C) Thermal Resistance Junction–to–Ambient

Thermal Resistance Junction–to–Case Operating Junction Temperature Operating Ambient Temperature (Notes 1 and 2) Storage Temperature Range

NOTE: ESD data available upon request

R R

T

P

θJA θJC

T

stg

D

J

A

0 to +70

–55 to +125

7.0 18

0.60 91 60

125

V V

Á

V V

W

°C/W °C/W

°C °C °C

2

MOTOROLA ANALOG IC DEVICE DATA

MC33470

ÁÁÁ

ÁÁÁ ÁÁÁ

ÁÁÁ

ÁÁÁ ÁÁÁ

ELECTRICAL CHARACTERISTICS (V

min/max values TA is the operating ambient temperature range that applies, unless otherwise noted.)

Characteristic

= 5.0 V, P

CC

, = 12 V for typical values TA = Low to High [Notes 1, 2, 3], for

P

VCC

V

CC

Symbol Min Typ Max Unit

OSCILLAT OR

Frequency (VCC = 4.5 to 5.5 V)

f

osc

210

FEEDBACK AMPLIFIER

Voltage Feedback Input Threshold (Note 4)

VID0, VID1, VID2 and VID4 = “1” and VID3 = “0”

VID4 = “1” and VID0, VID1, VID2 and VID3 = “0” Input Bias Current (VCM = 2.8 V) Transconductance (VCM = 2.8 V, V Open Loop Voltage Gain (V

COMP

= 2.0 V)

Output Line Regulation (VCC = 4.5 to 5.5 V) Output Load Regulation

V

sense

A

Reg

I

IB

G

M

VOL

load

line

1.764

2.744

3.43 –

400

– – –

Output Current

Source Sink

I

OH

OL

– –

PWM SECTION

Duty Cycle at G1 Output

Maximum Minimum

DC

max

min

77

–

Propagation Delay

Comp Input to G1 Output, TJ = 25°C Comp Input to G2 Output, TJ = 25°C

t

PLH1

t

PLH2

– –

SOFT–START SECTION

Charge Current (V

Soft–Start

Discharge Current under Current Limit (Note 5)

(V

Soft–Start

= 2.0 V, V

Discharge Current under Hard Current Limit

(V

Soft–Start

= 2.0 V, V

Hard Current Limit Hold Time

sense

= 0 V)

= V

< V

out

, V

/2, V

imax

= VCC, V

ifb

= 0 V)

I

chg

I

SSIL

I

SSHIL

t

SSHIL

7.0 30

40

100

IMAX INPUT

Sink Current (Vin

max

= VCC, V

= VCC)

ifb

I

OL

133

POWER GOOD OUTPUT

Threshold For Logic “1” to “0” Transition

Upper Threshold Lower Threshold

Response Time

Logic “0” to “1” (V Logic “1” to “0” (V

changes from 0 V to VO)

sense

changes from VO to 0 V)

sense

Sink Current (VOL = 0.5 V) Output Low Voltage (IOL = 100 µA) (Note 6)

NOTES: 1. Maximum package power dissipation limits must be observed.

2.Low duty cycle pulse techniques are used during test to maintain junction temperature as close to ambient as possible.

3.VID1, VID3, VID4 = logic 0, and VID0, VID2 = logic 1.

4.V

5.Under a typical soft current limit, the net soft–start discharge current will be 90 µA (I 6 Sense (Pin 6) = 5.0 V, Comp (Pin 10) open, VID4, VID2, VID1, VID0 = 1.0, VID3 = 0.

7.OUTEN is internally pulled low if VID0, 1, 2, 3, and 4 are floating.

8.Due to internal pull–up resistors, there will be an additional 0.5 mA per pin if any of the VID0, 1, 2, 3, or 4 pins are pulled low.

is provided from a low impedance voltage source or shorted to the output voltage.

sense

sink to source current ratio is designed to be 9:1.

V

t

rPG

I

OLPG

V

OLPG

th

SSIL

) – 10 µA (I

–

0.93

200

50

– –

chg

300

1.8

2.8

3.5 20

800

67

7.0

5.0

120 120

88

–

0.1

10 90

64

200

190

1.04

0.96

400 100

10

250

) = 80 µA. The softstart

390

1.836

2.856

3.57 –

1200

– – –

– –

95

0

– –

13

150

–

300

247

1.07 –

600 150

–

500

kHz

µA

µmho

dB mV mV

µA

mA

µA

V

sense

mA mV

V V V

%

µs

MOTOROLA ANALOG IC DEVICE DATA

3

MC33470

ÁÁÁ

ÁÁÁ ÁÁÁ

ÁÁÁ

ÁÁÁ ÁÁÁ

ÁÁÁ

ÁÁÁ ÁÁÁ

ÁÁÁ

ELECTRICAL CHARACTERISTICS

min/max values TA is the operating ambient temperature range that applies, unless otherwise noted.)

(continued) (VCC = 5.0 V, P

, = 12 V for typical values TA = Low to High [Notes 1, 2, 3], for

P

VCC

V

CC

Characteristic UnitMaxTypMinSymbol

FAULT OUTPUT

Threshold For Logic “0” to “1” Transition V

Response Time Switches from 2.8 V to V

sense

Sink Current (VOL = 0.5 V)

CC

V

t

I

OLF

thF rF

1.12 50

–

OVERTEMPERATURE OUTPUT

Threshold For Logic “1” to “0” Transition (OUTEN V oltage Decreasing) Delay Time Sink Current (VOL = 0.5 V)

V

thOUTEN

t

DOT

I

OLF

1.85 25

–

LOGIC INPUTS (VID0, VID1, VID2, VID3, VID4)

Input Low State Input High State Input Impedance

V

IL

V

IH

R

in

–

3.5 –

OUTPUT ENABLE CONTROL (OUTEN)

Over–Temperature Driver Disable and Reset

V

OTDD

1.55

(OUTEN Voltage Decreasing) (Note 7)

OUTPUT SECTIONS (G1, G2)

= 1.0 mA)

sink

P

VCC

V

– 1.0 V)

CC

Source Resistance (V

Sink Resistance (V

= 2.0 V, VG = P

sense

= 0 V, VG = 1.0 V)

sense

Output Voltage with OUTEN Reset (I Output Voltage Rise T ime (CL = 10 nF, TJ = 25°C) Output Voltage Fall T ime (CL = 10 nF, TJ = 25°C) G1, G2 Non–Overlap Time (CL = 10 nF, TJ = 25°C)

R

V

t

NOL

OH OL

OL t

r

t

f

– 0.5 – Ω –

– – –

30

TOTAL DEVICE

Minimum Operating Voltage After Turn–On (P

P

VCC

V

CC

Decreasing)

Minimum Operating Voltage After Turn–On (VCC Decreasing) VCC Current (Note 8) (OUTEN and P

P

VCC

V

CC

open,

P

V

CC min

VCC

I

min

CC

10.8 – – V

3.0 – 3.7 8.0 mA

VID0, 1, 2, 3, 4 Floating)

P

Current (OUTEN = 5.0 V, VID0, 1, 2, 3, 4 Open, P

VCC

V

CC

NOTES: 1. Maximum package power dissipation limits must be observed.

2.Low duty cycle pulse techniques are used during test to maintain junction temperature as close to ambient as possible.

3.VID1, VID3, VID4 = logic 0, and VID0, VID2 = logic 1.

4.V

5.Under a typical soft current limit, the net soft–start discharge current will be 90 µA (I 6 Sense (Pin 6) = 5.0 V, Comp (Pin 10) open, VID4, VID2, VID1, VID0 = 1.0, VID3 = 0.

7.OUTEN is internally pulled low if VID0, 1, 2, 3, and 4 are floating.

8.Due to internal pull–up resistors, there will be an additional 0.5 mA per pin if any of the VID0, 1, 2, 3, or 4 pins are pulled low.

is provided from a low impedance voltage source or shorted to the output voltage.

sense

sink to source current ratio is designed to be 9:1.

P

VCC

V

CC

= 12 V)

P

I

CC

SSIL

) – 10 µA (I

– 15 – mA

chg

1.14 100

10

2.0 50 10

– –

10

1.70

0.5

0.1 70 70

150

–

) = 80 µA. The softstart

1.2

150

–

2.2

100

–

0.8 – –

1.85

–

0.5

140 140 210

4.25

V

µs

mA

µs

mA

kΩ

ns ns ns

ref

V

V V

V

4

MOTOROLA ANALOG IC DEVICE DATA

Figure 1. Output Drive Waveform Figure 2. 5.0 V Supply Current

2.0 V/DIV500 mV/DIV50 mV/DIV VO = 2.8 V

IO = 3.3 A Figure 13 Circuit

200 nS/DIV

Figure 3. Error Amplifier Transient Response

MC33470

8.0

7.0

6.0

5.0

4.0

3.0

, SUPPLY CURRENT (mA)

2.0

CC

I

1.0 0

0

–0.5

–1.0

TA = 25°C

P

+

12 V

V

CC

P

+

Open

V

CC

0 1.0 2.0 3.0 4.0 5.0 6.0

INPUT VOLTAGE (V)

7.0

Figure 4. Drive Output Source/Sink Saturation

V oltage versus Load Current

P

Source Saturation

(Load to Ground)

V

8.0

CC

VO = 2.8 V

0

IO transient = 0.3 to 16 A

Figure 13 Circuit

2.5 mS/DIV

1.0

0.5

0

Figure 5. Feedback Circuit Load

Transient Response

20

VO = 2.8 V IO transient = 0.3 to 16 A Figure 13 Circuit

2.5 mS/DIV

15

10

5.0

LOOP GAIN (dB)

0

–5.0

–10

300

Sink Saturation (Load to P

0 0.2 0.4 0.6 0.8 1.0 1.2

)

V

CC

Ground

Figure 6. Feedback Loop Gain and Phase

versus Frequency

V

= 12 V

CCP

VCC = 5.0 V

VO = 2.8 V IO = 3.3 A

°

C

TA = 25

1.0 k 10 k 100 k 300 k3.0 k 30 k

Gain

Phase

f, FREQUENCY (Hz)

0

30

60

90

120

, EXCESS PHASE (DEGREES)

∅

150

180

MOTOROLA ANALOG IC DEVICE DATA

5