MAXIM MAX8553, MAX8554 User Manual

________________________________

概述

MAX8553为 4.5V至 28V输入、同步降压型控制器，为 DDR存储器提供完整的电源管理方案。MAX8553为VTT 和VTTR提供1/2 V

REFIN

电压。VTT和 VTTR跟踪电压保

持在1%的1/2 V

REFIN

范围内。MAX8554为 4.5V至28V输

入、非跟踪降压型控制器，具有极低的0.6V反馈门限电压。

MAX8553/MAX8554采用Maxim专有的Quick-PWMTM结构，以提供快速的瞬态响应并工作于可选的伪固定频率。这两个控制器工作时无须外部偏置电源。

该类控制器工作于同步整流模式，以保证高达25A的平衡源出电流和吸流能力。MAX8553/MAX8554能够提供高达95%的效率，非常适合服务器和负载点应用。另外，极低的5µA 关断电流使笔记本电脑应用中的电池寿命更长。无损耗电流监测是通过监视低端MOSFET的漏源电压实现的。MAX8553/MAX8554具有可调的折返电流限制，以承受连续的输出过载和短路。数字式软启动提供上电时对浪涌电流的控制。过压保护关断转换器并将输出电容放电。MAX8553/MAX8554采用节省空间的16引脚QSOP封装。

________________________________

应用

宽输入电源

服务器和存储系统应用

ASIC和CPU核电源

笔记本和LCD-PC电源

DDR I和DDR II存储器电源

AGTL总线端接电源

________________________________

特性

♦ 高达25A的输出电流 ♦ Quick-PWM控制结构提供快速的环路响应 ♦ 高达95%的效率 ♦ 4.5V至28V输入电压范围 ♦ 无需外部偏置电源 ♦ 0至3.6V输入REFIN电压范围(MAX8553) ♦ 自动设置VTT和VTTR至±1%精度的

1/2 V

REFIN

- (MAX8553)

♦ 极低的0.6V反馈门限电压(MAX8554) ♦ 200kHz/300kHz/400kHz/550kHz可选开关频率 ♦ 可调的折返电流限制 ♦ 过压保护 ♦ 数字软启动

MAX8553/MAX8554

4.5V至28V输入、同步PWM降压控制器，适合于DDR端接以及负载点应用

________________________________________________________________ Maxim Integrated Products 1

____________________________

定购信息

MAX8553

EN/HSD

+5V

POK

VIN

VOUT

VTTR

V+

REFIN

VTTRGND

POK

REFIN

BST

V+

REF

ILIM

FSEL

PGND

VTT

PART TEMP RANGE PIN-PACKAGE

MAX8553EEE -40°C to +85°C 16 QSOP

MAX8554EEE -40°C to +85°C 16 QSOP

_________________________

典型工作电路

19-3017; Rev 1; 5/05

本文是

Maxim

正式英文资料的译文，

Maxim

不对翻译中存在的差异或由此产生的错误负责。请注意译文中可能存在文字组织或

翻译错误，如需确认任何词语的准确性，请参考

Maxim

提供的英文版资料。

索取免费样品和最新版的数据资料，请访问

Maxim

的主页：

www.maxim-ic.com.cn

。

引脚配置在数据资料的最后给出。

Quick-PWM是Maxim Integrated Products, Inc.

的商标。

MAX8553/MAX8554

4.5V至28V输入、同步PWM降压控制器，适合于DDR端接以及负载点应用

2 _______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

ELECTRICAL CHARACTERISTICS

(VV+= V

HSD

= +12V, V

EN/HSD

= V

REFIN

= +2.5V, VEN= +5V, C

= 4.7µF, C

VTTR

= 1µF, C

REF

= 0.22µF, V

FSEL

= 0V, ILIM = VL,

PGND = LX = GND, BST = VL, T

= 0°C to +85°C. Typical values are at TA= +25°C, unless otherwise specified.)

Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.

V+, EN/HSD, EN, HSD to GND...............................-0.3V to +30V

PGND to GND .......................................................-0.3V to +0.3V

VTT, REFIN, POK, OUT, FB, VL to GND...................-0.3V to +6V

REF, VTTR, DL, ILIM, FSEL to GND ............-0.3V to (V

+ 0.3V)

LX to PGND ...............................................................-2V to +30V

BST to GND ............................................................-0.3V to +36V

DH to LX ...................................................................-0.3V to +6V

LX to BST..................................................................-6V to +0.3V

REF Short Circuit to GND ...........................................Continuous

Continuous Power Dissipation (T

= +70°C)

16-Pin QSOP (derated 8.3mW/°C above +70°C) ........667mW

Operating Temperature Range ...........................-40°C to +85°C

Junction Temperature......................................................+150°C

Storage Temperature Range .............................-65°C to +150°C

Lead Temperature (soldering, 10s) .................................+300°C

V+ Input Voltage Range VL not connected to V+ 6 28 V

V+ Input Voltage Range VL connected to V+ 4.5 5.5 V

EN/HSD Input Voltage Range MAX8553 enabled 1.5 28.0 V

EN Input Voltage Range MAX8554 enabled 1.5 28.0 V

EN Input Current 23µA

HSD Input Voltage Range MAX8554 enabled 1.5 28.0 V

HSD Input Current 20 40 µA

REFIN Input Voltage Range 0 3.6 V

V+ Supply Current (MAX8553) V

V+ Supply Current (MAX8554) V

REFIN Supply Current 125 250 µA

EN/HSD Supply Current 510µA

VL Supply Current V

V+ Shutdown Supply Current EN/HSD = GND 3 5 µA

REFIN Shutdown Supply Current EN/HSD = GND 1 µA

VL Shutdown Supply Current V

VL Undervoltage-Lockout Threshold Rising edge, typical hysteresis = 40mV 4.05 4.25 4.40 V

VTT

VTT Input Bias Current V

VTT Feedback Voltage Range 0 1.8 V

VTT Feedback Voltage Accuracy

FB Input Bias Current MAX8554, V

PARAMETER CONDITIONS MIN TYP MAX UNITS

= +1.35V 0.8 1.2 mA

VTT

= 630mV 0.62 0.90 mA

= V

VTT

REFIN

= 5.5V, V

V+

= V

= +5.5V, V

V+

= +1.25V -0.15 0 µA

= V

EN/HSD

= V

EN/HSD

VTT

EN/HSD

= +1.8V 49.5 50 50.5

= +3.6V 49.5 50 50.5

= +600mV -0.15 0 µA

= +1.35V 0.8 1.2 mA

= 0V 5 12 µA

% V

RE FIN

MAX8553/MAX8554

4.5V至28V输入、同步PWM降压控制器，适合于DDR端接以及负载点应用

_______________________________________________________________________________________ 3

ELECTRICAL CHARACTERISTICS (continued)

(VV+= V

HSD

= +12V, V

EN/HSD

= V

REFIN

= +2.5V, VEN= +5V, C

= 4.7µF, C

VTTR

= 1µF, C

REF

= 0.22µF, V

FSEL

= 0V, ILIM = VL,

PGND = LX = GND, BST = VL, T

= 0°C to +85°C. Typical values are at TA= +25°C, unless otherwise specified.)

FB Regulation Voltage MAX8554, V

Output Adjust Range MAX8554 (Note 1) 0.6 3.5 V

VTT Line Regulation V

FB Line Regulation

VTT Load Regulation 0 < I

FB Load Regulation

REFERENCE

Reference Output Voltage V

Reference Load Regulation V

Reference UVLO V

VTTR

VTTR Output Voltage Range 0 1.8 V

VTTR Output Accuracy

PARAMETER CONDITIONS MIN TYP MAX UNITS

= +2.5V, FSEL unconnected 0.598 0.607 0.616 V

OUT

±10%, V

EN/HSD

MAX8554, V I

OUT

MAX8554, 0 < I FSEL unconnected

V+

VTTR

HSD

= 0A, FSEL unconnected

< +7A, V

OUT

= V

= +4.5 to +5.5V, I

= V

= +5V, I

= V

= +5V, reference rising, hysteresis = 27mV 1.5 1.6 1.7 V

= -5mA to +5mA 49.5 50 50.5

= -25mA to +25mA, V

VTT

±10%, V

VTT

< +7A, V

OUT

REF

= +1.25V, I

= 0A ±0.325 %

OUT

= +2.5V,

OUT

= +1.25V 0.2 %

= +2.5V,

OUT

= 0 1.97 2.00 2.03 V

REF

= 0 to 50µA 10 mV

= +1.8V 49 50 51

REFIN

= +3.6V 49.5 50 50.5

REFIN

±0.325 %

0.2 %

% V

Thermal Shutdown Rising temperature, typical hysteresis = 15°C +160 °C

SOFT-START

ILIM Ramp Period

Output Predischarge Period

OSCILLATOR

Ramps the ILIM trip threshold from 20% to 100% in

20% increments

Rising edge of EN/HSD to the start of internal digital

soft-start

0.8

1.7 3.0 ms

FSEL = VL 200 

Oscillator Frequency

FSEL = unconnected 300  FSEL = REF 400  FSEL = GND 550 

FSEL = VL 2.18 2.5 2.83

On-Time

MAX8553, V

(Note 2)

VTT

= +1.25V

FSEL unconnected 1.45 1.67 1.89 FSEL = REF 1.09 1.25 1.41 FSEL = GND 0.82 0.91 1.00 FSEL = VL 0.89 1.02 1.16

On-Time

MAX8554, V

(Note 2)

OUT

= +2.5V

FSEL unconnected 0.61 0.71 0.80 FSEL = REF 0.43 0.49 0.56 FSEL = GND 0.33 0.37 0.41

Off-Time (Note 2) 350 400 ns

RE FIN

kHz



µs

MAX8553/MAX8554

4.5V至28V输入、同步PWM降压控制器，适合于DDR端接以及负载点应用

4 _______________________________________________________________________________________

ELECTRICAL CHARACTERISTICS (continued)

(VV+= V

HSD

= +12V, V

EN/HSD

= V

REFIN

= +2.5V, VEN= +5V, C

= 4.7µF, C

VTTR

= 1µF, C

REF

= 0.22µF, V

FSEL

= 0V, ILIM = VL,

PGND = LX = GND, BST = VL, T

= 0°C to +85°C. Typical values are at TA= +25°C, unless otherwise specified.)

CURRENT LIMIT

Current-Limit Threshold (Positive Direction)

Current-Limit Threshold (Negative Direction)

ILIM Input Current 5µA

FAULT DETECTION

VL REGULATOR

Output Voltage +6V < V Line Regulation +6V < V RMS Output Current 35 mA Bypass Capacitor ESR < 100mΩ 2.2 µF

DRIVER

DH Gate-Driver On-Resistance V

DL Gate-Driver On-Resistance (Source)

DL Gate-Driver On-Resistance (Sink)

Dead Time

FSEL LOGIC

Logic Input Current -3 +3 µA

Logic Low (GND) 0.5 V

Logic REF Level FSEL = REF 1.65 2.35 V

Logic Float Level FSEL unconnected 3.15 3.85 V

Logic VL Level FSEL = VL VVL - 0.4 V

EN/HSD OR EN LOGIC

EN/HSD or EN Shutdown Current Max I

Logic High V

Logic Low V

PARAMETER CONDITIONS MIN TYP MAX UNITS

LX to PGND, ILIM = VL 80 100 115

LX to PGND, R

LX to PGND, ILIM = VL, with respect to positive current-limit threshold

MAX8553 (V

MAX8554 0.696 0.720 0.744

V+

- V

BST

DL high state 1.6 3.0 Ω

DL low state 0.75 1.25 Ω

DL rising 32

DL falling 30

= +5V 1.4 2.5 Ω

EN/HSD

= V

= +4.5 to +5.5V, 100mV hysteresis 1.5 V

V+

= V

= +4.5 to +5.5V 0.8 V

V+

= 100kΩ 35 50 65

ILIM

= 400kΩ 160 200 230

ILIM

> +1V) 57 60 63 % V

REFIN

≤ +1V) 0.576 0.600 0.624Overvoltage Threshold

REFIN

<+28V, 1mA < I

< +28V, IVL = 10mA 0.2 %

for V

EN/HSD

< 35mA 4.80 5.0 5.33 V

< +0.8V or VEN < +0.8V 0.5 3.0 µA

-130 -110 -90 %

RE FIN

MAX8553/MAX8554

4.5V至28V输入、同步PWM降压控制器，适合于DDR端接以及负载点应用

_______________________________________________________________________________________ 5

ELECTRICAL CHARACTERISTICS (continued)

(VV+= V

HSD

= +12V, V

EN/HSD

= V

REFIN

= +2.5V, VEN= +5V, C

= 4.7µF, C

VTTR

= 1µF, C

REF

= 0.22µF, V

FSEL

= 0V, ILIM = VL,

PGND = LX = GND, BST = VL, T

= 0°C to +85°C. Typical values are at TA= +25°C, unless otherwise specified.)

ELECTRICAL CHARACTERISTICS

V+

= V

HSD

= +12V, V

EN/HSD

= V

REFIN

= +2.5V, V

= +5V, C

= 4.7µF, C

VTTR

= 1µF, C

REF

= 0.22µF, V

FSEL

= 0, ILIM = VL, PGND

= LX = POK = GND, BST = VL, T

= -40°C to +85°C, unless otherwise specified.) (Note 3)

POWER-OK OUTPUT

Upper VTT and VTTR Threshold MAX8553 55 56 57 % V

Lower VTT and VTTR Threshold MAX8553 43 44 45 % V

Upper Threshold MAX8554 0.646 0.672 0.698 V

Lower Threshold MAX8554 0.504 0.528 0.552 V

POK Output Low Level I

POK Output High Leakage V

PARAMETER CONDITIONS MIN TYP MAX UNITS

= 2mA 0.4 V

SINK

= +5V 5 µA

POK

RE FIN

V+ Input Voltage Range VL not connected to V+ 6 28 V

V+ Input Voltage Range VL connected to V+ 4.5 5.5 V

EN/HSD Input Voltage Range MAX8553 enabled 1.5 28.0 V

EN Input Voltage Range MAX8554 enabled 1.5 28.0 V

EN Input Current 3µA

HSD Input Voltage Range MAX8554 enabled 1.5 28.0 V

HSD Input Current 40 µA

REFIN Input Voltage Range 0 3.6 V

V+ Supply Current (MAX8553) V

V+ Supply Current (MAX8554) V

REFIN Supply Current 250 µA

EN/HSD Supply Current 10 µA

VL Supply Current V

V+ Shutdown Supply Current EN/HSD = GND 5 µA

REFIN Shutdown Supply Current EN/HSD = GND 1 µA

VL Shutdown Supply Current V

VL Undervoltage-Lockout Threshold Rising edge, typical hysteresis = 40mV 4.05 4.40 V

VTT

VTT Input Bias Current V

VTT Feedback Voltage Range 0 1.8 V

VTT Feedback Voltage Accuracy

FB Input Bias Current MAX8554, V

FB Regulation Voltage MAX8554, V

Output Adjust Range MAX8554 (Note 1) 0.6 3.5 V

PARAMETER CONDITIONS MIN MAX UNITS

= +1.35V 1.2 mA

VTT

= 630mV 0.90 mA

= VV+ = 5.5V, V

= V

VTT

REFIN

= +5.5V, V

V+

= +1.25V -0.2 0 µA

= V

EN/HSD

= V

EN/HSD

= +600mV -0.2 0 µA

OUT

= +1.35V 1.2 mA

VTT

= 0V 12 µA

EN/HSD

= +1.8V 49.5 50.5

= +3.6V 49.5 50.5

= +2.5V, FSEL unconnected 0.598 0.616 V

% V

RE FIN

MAX8553/MAX8554

4.5V至28V输入、同步PWM降压控制器，适合于DDR端接以及负载点应用

6 _______________________________________________________________________________________

ELECTRICAL CHARACTERISTICS (continued)

V+

= V

HSD

= +12V, V

EN/HSD

= V

REFIN

= +2.5V, V

= +5V, C

= 4.7µF, C

VTTR

= 1µF, C

REF

= 0.22µF, V

FSEL

= 0, ILIM = VL, PGND

= LX = POK = GND, BST = VL, T

= -40°C to +85°C, unless otherwise specified.) (Note 3)

REFERENCE

Reference Output Voltage V

Reference Load Regulation V

Reference UVLO V

VTTR

VTTR Output Voltage Range 0 1.8 V

SOFT-START

ILIM Ramp Period

Output Predischarge Period

OSCILLATOR

On-Time

Off-Time (Note 2) 420 ns

CURRENT LIMIT

Current-Limit Threshold (Positive Direction)

Current-Limit Threshold (Negative Direction)

ILIM Input Current µA

FAULT DETECTION

Overvoltage Threshold

VL REGULATOR Output Voltage +6V < V RMS Output Current 35 mA Bypass Capacitor ESR < 100mΩ 2.2 µF

PARAMETER CONDITIONS MIN MAX UNITS

= V

V+

= V

V+

= V

V+

= -5mA to +5mA 49.5 50.5

VTTR

= -25mA to +25mA, V

VTTR

= -25mA to +25mA, V

VTTR

= +4.5 to +5.5V, I

= +5V, I

REF

= +5V, reference rising, hysteresis = 27mV 1.5 1.7 V

REF

= 0 to 50µA 10 mV

REFIN

= 0 1.97 2.03 V

= +1.8V 49 51VTTR Output Accuracy

= +3.6V 49.5 50.5

Ramps the ILIM trip threshold from 20% to 100% in

20% increments

Rising edge of EN/HSD to the start of internal digital

soft-start

0.8

3.0 ms

FSEL = VL 2.18 2.83

MAX8553, V

(Note 2)

VTT

= +1.25V

FSEL unconnected 1.45 1.89 FSEL = REF 1.09 1.41 FSEL = GND 0.82 1.00 FSEL = VL 0.89 1.16

MAX8554, V

(Note 2)

OUT

= +2.5V

FSEL unconnected 0.61 0.80 FSEL = REF 0.43 0.56 FSEL = GND 0.33 0.41

LX to PGND, ILIM = VL 80 115

LX to PGND, R

LX to PGND, ILIM = VL, with respect to positive current-limit threshold

MAX8553 (V

MAX8554 0.696 0.744

V+

= 100kΩ 30 65

ILIM

= 400kΩ 150 230

ILIM

-130 -90 %

> +1V) 57 63

REFIN

≤ +1V) 0.576 0.624

REFIN

< +28V, 1mA < I

< 35mA 4.80 5.33 V

% V

RE FIN

µs

MAX8553/MAX8554

4.5V至28V输入、同步PWM降压控制器，适合于DDR端接以及负载点应用

_______________________________________________________________________________________ 7

ELECTRICAL CHARACTERISTICS (continued)

V+

= V

HSD

= +12V, V

EN/HSD

= V

REFIN

= +2.5V, V

= +5V, C

= 4.7µF, C

VTTR

= 1µF, C

REF

= 0.22µF, V

FSEL

= 0, ILIM = VL, PGND

= LX = POK = GND, BST = VL, T

= -40°C to +85°C, unless otherwise specified.) (Note 3)

Note 1: Consult factory for applications that require higher than 3.5V output. Note 2: On-time and off-time specifications are measured from 50% point to 50% point at the DH pin with LX forced to 0V, BST

forced to 5V, and a 250pF capacitor connected from DH to LX. Actual in-circuit times may differ due to MOSFET switching speeds.

Note 3: Specifications to -40°C are guaranteed by design and are not production tested.

DRIVER

DH Gate-Driver On-Resistance V

DL Gate-Driver On-Resistance (Source)

DL Gate-Driver On-Resistance (Sink)

FSEL LOGIC

Logic Input Current -3 +3 µA

Logic Low (GND) 0.5 V

Logic REF Level FSEL = REF 1.65 2.35 V

Logic Float Level FSEL unconnected 3.15 3.85 V

Logic VL Level FSEL = VL V

EN/HSD OR EN LOGIC

EN/HSD or EN Shutdown Current Max I

Logic High V

Logic Low V

POWER-OK OUTPUT

Upper VTT, and VTTR Threshold MAX8553 55 57 % V

Lower VTT, and VTTR Threshold MAX8553 43 45 % V

Upper Threshold MAX8554 0.646 0.698 V

Lower Threshold MAX8554 0.504 0.552 V

POK Output Low Level I

POK Output High Leakage V

PARAMETER CONDITIONS MIN MAX UNITS

- V

BST

DL high state 3.0 Ω

DL low state 1.25 Ω

EN/HSD

= V

= 2mA 0.4 V

SINK

= +5V 5 µA

POK

= +5V 2.5 Ω

for V

EN/HSD

= +4.5 to +5.5V, 100mV hysteresis 1.5 V

V+

= +4.5 to +5.5V 0.8 V

V+

< +0.8V or VEN < +0.8V 0.5 3.0 µA

- 0.4 V

RE FIN

1.19

1.23

1.21

1.27

1.25

1.29

1.31

04268

LOAD REGULATION

(CIRCUIT OF FIGURE 2)

MAX8553/4 toc09

LOAD CURRENT (A)

OUTPUT VOLTAGE (V)

VTT CONNECTED AS SHOWN IN FIGURE 2

VTT CONNECTED TO THE OUTPUT

MAX8553/MAX8554

4.5V至28V输入、同步PWM降压控制器，适合于DDR端接以及负载点应用

8 _______________________________________________________________________________________

_________________________________________________________________

典型工作特性

V+

= 12V, V

OUT

= 1.8V, circuit of Figure 1, TA = +25°C, unless otherwise noted.)

100

0.1 1.0 10.0

EFFICIENCY vs. LOAD CURRENT

(CIRCUIT OF FIGURE 2)

MAX8553/4 toc01

LOAD CURRENT (A)

EFFICIENCY (%)

VIN = 1.8V V

OUT

= 0.9V

VIN = 2.5V V

OUT

= 1.25V

0.1 10.0 100.0

EFFICIENCY vs. LOAD CURRENT

(CIRCUIT OF FIGURE 1)

MAX8553/4 toc02

LOAD CURRENT (A)

EFFICIENCY (%)

1.0

100

OUT

= 1.8V

OUT

= 2.5V

400

450

550

500

600

650

-8 -4 -2-6 02468

SWITCHING FREQUENCY vs.

OUTPUT CURRENT (CIRCUIT OF FIGURE 2)

MAX8553/4 toc03

OUTPUT CURRENT (A)

SWITCHING FREQUENCY (kHz)

200

240

220

280

260

300

320

6 8 10 12 14 16 18 20 22 24 26 28

SWITCHING FREQUENCY

vs. INPUT VOLTAGE (CIRCUIT OF FIGURE 3)

MAX8553/4 toc04

INPUT VOLTAGE (V)

SWITCHING FREQUENCY (kHz)

160

180

170

200

190

210

220

-40 -15 10 35 60 85

FREQUENCY vs. TEMPERATURE

MAX8553/4 toc05

TEMPERATURE (°C)

FREQUENCY (kHz)

4.0

3.5

3.0

2.5

2.0

1.5

1.0

0.5

4.5

5.0

4 8 12 16 20 24 28

MAX8554 SHUTDOWN SUPPLY CURRENT

vs. INPUT VOLTAGE

MAX8553/4 toc06

INPUT VOLTAGE (V)

SHUTDOWN SUPPLY CURRENT (μA)

V+ = HSD, EN = GND

4.0

3.5

3.0

2.5

2.0

1.5

1.0

0.5

4.5

5.0

4 8 12 16 20 24 28

MAX8553 SHUTDOWN SUPPLY CURRENT

vs. INPUT VOLTAGE

MAX8553/4 toc07

INPUT VOLTAGE (V)

SHUTDOWN SUPPLY CURRENT (μA)

EN = GND

1.74

1.78

1.76

1.82

1.80

1.84

1.86

0 4.0 8.0 12.0 16.0 20.0

LOAD REGULATION

(CIRCUIT OF FIGURE 1)

MAX8553/4 toc08

LOAD CURRENT (A)

OUTPUT VOLTAGE (V)

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