Datasheet

ManualsBrandsMAXIM INTEGRATED ManualsPMICsPMIC - hot swap controller Multi-purpose TQFN 20 Surface-mount

1V to 16V, Single-Channel, Hot-Swap Controllers

with Precision Current-Sensing Output

MAX5977A/MAX5977B

EVALUATION KIT AVAILABLE

General Description

The MAX5977A/MAX5977B hot-swap controllers provide

complete protection for systems with a 1V to 16V single-

supply voltage.

During the initial insertion, the hot-swap controllers

limit the inrush current from damaging the board or

from shorting out the backplane. When the input volt-

age is above the undervoltage threshold and below the

overvoltage threshold, a 5FA current source powered

from the internal 5V charge pump drives the gate of an

external n-channel MOSFET, providing a slow turn-on

response. An internal current-sense amplifier in the IC

monitors the current across an external shunt resistor,

providing current sensing for wide input-sense voltage

range. The devices provide two levels of overcurrent

circuit-breaker protections: a fast-trip threshold for a fast

turn-off and a lower slow-trip threshold for a delayed

turn-off.

Exceeding either of the overcurrent circuit-breaker

thresholds forces the device into fault mode where the

external n-channel MOSFET is disabled. The MAX5977

is available in two versions that provide a latched-off

(MAX5977A) or autoretry (MAX5977B) output when the

device is in fault mode.

A calibration mode allows further calibration of the inte-

grated transconductance amplifier for production testing

of the final design. The devices are offered in a 20-pin,

4mm x 4mm, TQFN-EP package and are fully specified

from -40NC to +85NC.

Features

S 1% Accurate Current-Sense Amplifier Output

S Hot-Swap Monitors Operation from 1V to 16V

S Integrated Charge Pump Fully Enhances the

External n-Channel FET (V

GATE

= V

+ 5V)

S VariableSpeed/BiLevelK Fault Protection Provides

Electronic Circuit-Breaker Function

S Output Latched Off After Fault Condition

(MAX5977A)

S Autoretry After Fault Condition (MAX5977B)

S Power-Good Indicator

S Calibration Mode

S Small, 20-Pin, 4mm x 4mm TQFN-EP Package

Applications

Servers

Storage Systems

Network Switches and Routers

General Hot-Swap

19-5553; Rev 2; 7/11

Ordering Information

Typical Operating Circuit

VariableSpeed/BiLevel is a trademark of Maxim Integrated

Products, Inc.

Note: All devices are specified over the -40NC to +85NC oper-

ating temperature range.

+Denotes a lead(Pb)-free/RoHS-compliant package.

*EP = Exposed pad.

MAX5977A

MAX5977B

CALSENSE

SOURCE

CSOUT

FAULT

CAL

PWR

AGND

SCOMP FCOMP IN SENSE GATE

GND

2.7V TO 16V

CALIBRATION

MODE INPUT

CAL

SCOMP

FCOMP

SENSE

GATE

+3.3V

CSOUT

GATE

TO LOAD

CURRENT-SENSE

AMPLIFIER OUTPUT

FAULT OUTPUT

POWER-GOOD OUTPUT

1V TO 16V

PART PIN-PACKAGE

FAULT RESPONSE

MAX5977AETP+ 20 TQFN-EP* Latched

MAX5977BETP+ 20 TQFN-EP* Autoretry

For pricing, delivery, and ordering information, please contact Maxim Direct

at 1-888-629-4642, or visit Maxim’s website at www.maximintegrated.com.

Summary of content (13 pages)

PAGE 1
EVALUATION KIT AVAILABLE MAX5977A/MAX5977B 1V to 16V, Single-Channel, Hot-Swap Controllers with Precision Current-Sensing Output General Description Features The MAX5977A/MAX5977B hot-swap controllers provide complete protection for systems with a 1V to 16V singlesupply voltage.
PAGE 2
MAX5977A/MAX5977B 1V to 16V, Single-Channel, Hot-Swap Controllers with Precision Current-Sensing Output ABSOLUTE MAXIMUM RATINGS PWR, SENSE, IN, FCOMP, SCOMP, GATE, SOURCE, CALSENSE to GND................-0.3V to +28V PG, CAL, BIAS, UV, OV, FAULT, CSOUT to GND...-0.3V to +6V REG to GND.............................................................-0.3V to +4V GATE to SOURCE....................................................-0.3V to +6V IN to FCOMP, IN to SCOMP, IN to SENSE, IN to CALSENSE....................
PAGE 3
MAX5977A/MAX5977B 1V to 16V, Single-Channel, Hot-Swap Controllers with Precision Current-Sensing Output ELECTRICAL CHARACTERISTICS (continued) (VPWR = VIN = 12V, RSENSE = 4mI, RFCOMP = RSCOMP = 2kI, RGATE = 1kI, CGATE = 330nF, CREG = 1FF, unless otherwise noted. Typical Values at VPWR = VIN = 3.3V, TA = +25NC, unless otherwise noted.) (Note 2) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS CURRENT-SENSE AMPLIFIER Input Common-Mode Range VIN - VSENSE 1.
PAGE 4
MAX5977A/MAX5977B 1V to 16V, Single-Channel, Hot-Swap Controllers with Precision Current-Sensing Output ELECTRICAL CHARACTERISTICS (continued) (VPWR = VIN = 12V, RSENSE = 4mI, RFCOMP = RSCOMP = 2kI, RGATE = 1kI, CGATE = 330nF, CREG = 1FF, unless otherwise noted. Typical Values at VPWR = VIN = 3.3V, TA = +25NC, unless otherwise noted.) (Note 2) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS 4.5 5 5.
PAGE 5
MAX5977A/MAX5977B 1V to 16V, Single-Channel, Hot-Swap Controllers with Precision Current-Sensing Output Typical Operating Characteristics (continued) (VPWR = VIN = 3.3V, TA = +25NC, RFCOMP = RSCOMP = 2kI, RGATE = 1kI, CGATE = 330nF, CREG = 1FF, unless otherwise noted.) VGATE vs. VIN I_COMP vs. TEMPERATURE IFCOMP 5.20 5.15 5.10 35 VGATE (V) I_COMP (µA) 40 MAX5977 toc05 50 45 5.25 MAX5977 toc04 55 30 25 20 ISCOMP 15 5.05 5.00 4.95 4.90 10 4.85 5 4.80 4.
PAGE 6
MAX5977A/MAX5977B 1V to 16V, Single-Channel, Hot-Swap Controllers with Precision Current-Sensing Output Typical Operating Characteristics (continued) (VPWR = VIN = 3.3V, TA = +25NC, RFCOMP = RSCOMP = 2kI, RGATE = 1kI, CGATE = 330nF, CREG = 1FF, unless otherwise noted.
PAGE 7
MAX5977A/MAX5977B 1V to 16V, Single-Channel, Hot-Swap Controllers with Precision Current-Sensing Output GATE GND CSOUT PG TOP VIEW SOURCE Pin Configuration 15 14 13 12 11 FAULT 16 CAL 17 MAX5977A MAX5977B I.C. 18 I.C. 19 EP* 1 2 3 4 5 REG PWR AGND UV OV BIAS 20 10 CALSENSE 9 SENSE 8 IN 7 SCOMP 6 FCOMP THIN QFN *CONNECT TO AGND. Pin Description PIN NAME 1 REG Regulator Output. Bypass REG with a 1FF capacitor. FUNCTION 2 PWR Power-Supply Input.
PAGE 8
MAX5977A/MAX5977B 1V to 16V, Single-Channel, Hot-Swap Controllers with Precision Current-Sensing Output Functional Diagram IN CS AMPLIFIER SENSE 0 CALSENSE CSOUT MUX S 1 CAL CHARGE PUMP MAX5977A MAX5977B OVERDRIVE DELAY 5µA 2MHz OSCILLATOR GATE SCOMP SLOW CB 25µA FCOMP SOURCE GATE PULLDOWN OD DELAY/ CB TIMER IN PG FAST CB 50µA 50ms PG TIMER IN - 100mV UV UVP 0.59V 10µA 10µA FAULT OV OVP 0.59V S POR UVLO Q GND R PWR REG BIAS 8 LDO REF/ BIAS AUTORETRY ENABLE 0.
PAGE 9
MAX5977A/MAX5977B 1V to 16V, Single-Channel, Hot-Swap Controllers with Precision Current-Sensing Output Detailed Description The hot-swap controllers provide electronic circuitbreaker protection and precision current sensing for a single-supply voltage from 1V to 16V. Programmable undervoltage and overvoltage protection qualifies the supply voltage prior to enhancing the external n-channel MOSFET with the internal gate driver.
PAGE 10
MAX5977A/MAX5977B 1V to 16V, Single-Channel, Hot-Swap Controllers with Precision Current-Sensing Output Power-Good Output The open-drain, active-high output PG indicates the power-good status of the output. Once the input voltage satisfies the undervoltage and overvoltage requirements for startup and VIN - VSOURCE is less than 100mV and the VGATE - VSOURCE > 4V, the PG timer is started. At the expiration of the 50ms PG timer, PG is asserted high.
PAGE 11
MAX5977A/MAX5977B 1V to 16V, Single-Channel, Hot-Swap Controllers with Precision Current-Sensing Output An output resistor, RCSOUT, must be connected between the transconductance current-sense amplifier output CSOUT and AGND. The transconductance GM, of the amplifier is typically 2500FS: (d = tSU/(tSU + tRETRY)). Calculate the required transient thermal resistance with the following equation: Z θJA(MAX) ≤ R CSOUT × G M × VSENSE, FS ≤ 2.
PAGE 12
MAX5977A/MAX5977B 1V to 16V, Single-Channel, Hot-Swap Controllers with Precision Current-Sensing Output Typical Application Circuit RSENSE VIN 1V TO 16V TO LOAD RSCOMP R1 SCOMP FCOMP IN SENSE UV 49.9I CGATE GATE SOURCE R2 MAX1393 ADC CSOUT OV 0.1µF RCSOUT R3 CALSENSE IN 125µA PRECISION CURRENT SOURCE CL RGATE RFCOMP MAX5977A MAX5977B OUTF OUTS GND 5.1kI 1µF +3.3V 4.99kI MAX6033AAUT25 10kI 2.7V TO 16V 10kI PWR 0.
PAGE 13
MAX5977A/MAX5977B 1V to 16V, Single-Channel, Hot-Swap Controllers with Precision Current-Sensing Output Revision History REVISION NUMBER REVISION DATE 0 9/10 Initial release — 1 1/11 Changed current-sense amplifier specifications in Electrical Characteristics table 3 2 7/11 Updated Electrical Characteristics specifications to reflect improved yield of part 2, 3 DESCRIPTION PAGES CHANGED Maxim Integrated cannot assume responsibility for use of any circuitry other than circuitry entirely embod