MAXIM MAX5921, MAX5939 Technical data

General Description

The MAX5921/MAX5939 hot-swap controllers allow a circuit card to be safely hot plugged into a live backplane. The MAX5921/MAX5939 operate from -20V to -80V and are well suited for -48V power systems. These devices are pin compatible with both the LT1640 and LT4250 and provide improved features over these devices.

The MAX5921/MAX5939 provide a controlled turn-on to circuit cards preventing damage to board connectors, board components, and preventing glitches on the power-supply rail. The MAX5921/MAX5939 provide undervoltage, overvoltage, and overcurrent protection. These devices ensure that the input voltage is stable and within tolerance before applying power to the load.

Both the MAX5921 and MAX5939 protect a system against overcurrent and short-circuit conditions by turning off the external MOSFET in the event of a fault condition. The MAX5921/MAX5939 protect against input voltage steps by limiting the load current to a safe level without turning off power to the load.

The device features an open-drain power-good status output, PWRGD or PWRGD for enabling downstream converters (see Selector Guide). A built-in thermal shutdown feature is also included to protect the external MOSFET in case of overheating. The MAX5939 features a latched fault output. The MAX5921 contains built-in autoretry circuitry after a fault condition.

The MAX5921/MAX5939 are available in an 8-pin SO package and operate in the extended -40°C to +85°C temperature range.

Applications

Telecom Line Cards

Network Switches/Routers

Central-Office Line Cards

Server Line Cards

Base-Station Line Cards

Features

♦ Allows Safe Board Insertion and Removal

from a Live -48V Backplane

♦ Pin-Compatible with LT1640 and LT4250

♦ Circuit Breaker Immunity to Input Voltage Steps

and Current Spikes

♦ 450mA GATE Pulldown Current During Short-

Circuit Condition

♦ Exponential GATE Pulldown Current

♦ Withstands -100V Input Transients with No

External Components

♦ Programmable Inrush and Short-Circuit Current

Limits

♦ Operates from -20V to -80V

♦ Programmable Overvoltage Protection

♦ Programmable Undervoltage Lockout

with Built-In Glitch Filter

♦ Overcurrent Fault Integrator

♦ Powers Up into a Shorted Load

♦ Power-Good Control Output

♦ Thermal Shutdown Protects External MOSFET

MAX5921/MAX5939

-48V Hot-Swap Controllers with External R

SENSE

and High Gate Pulldown Current

________________________________________________________________ Maxim Integrated Products 1

Pin Configuration

Ordering Information

19-2946; Rev 0; 9/03

For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at 1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.

Typical Operating Circuit and Selector Guide appear at end of data sheet.

Ordering Information continued at end of data sheet.

查询MAX5921供应商

PART TEMP RANGE PIN-PACKAGE

MAX5921AESA -40°C to +85°C 8 SO

MAX5921BESA -40°C to +85°C 8 SO

TOP VIEW

PWRGD

(PWRGD)

() FOR MAX5921B/F AND MAX5939B/F.

MAX5921 MAX5939

87V

DRAINOV

GATE

SENSEV

MAX5921/MAX5939

-48V Hot-Swap Controllers with External R

SENSE

and High Gate Pulldown Current

2 _______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

ELECTRICAL CHARACTERISTICS

(VEE= 0V, VDD= 48V, TA= -40°C to +85°C, unless otherwise noted. Typical values are at TA= +25°C, unless otherwise noted.) (Notes 1, 4)

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.

All Voltages Are Referenced to VEE, Unless Otherwise Noted Supply Voltage (VDD- V

)................................-0.3V to +100V

DRAIN, PWRGD, PWRGD ....................................-0.3V to +100V

PWRGD to DRAIN .............................................… -0.3V to +95V

PWRGD to VDD.......................................................-95V to +85V

SENSE (Internally Clamped) .................................-0.3V to +1.0V

GATE (Internally Clamped) ....................................-0.3V to +18V

UV and OV..............................................................-0.3V to +60V

Current into SENSE...........................................................+40mA

Current into GATE...........................................................+300mA

Current into Any Other Pin................................................+20mA

Continuous Power Dissipation (TA= +70°C)

8-Pin SO (derate 5.9mW/°C above +70°C)..................471mW

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

POWER SUPPLIES

Operating Input Voltage Range V

Supply Current I

GATE DRIVER AND CLAMPING CIRCUITS

Gate Pullup Current I

Gate Pulldown Current I External Gate Drive ∆V

GATE to VEE Clamp Voltage V

CIRCUIT BREAKER

Current-Limit Trip Voltage V

SENSE Input Current I

UNDERVOLTAGE LOCKOUT

Supply Internal Undervoltage Lockout Voltage High

Supply Internal Undervoltage Lockout Voltage Low

UV INPUT

UV High Threshold V

UV Low Threshold V

UV Hysteresis V

UV Input Current I

OV INPUT

OV High Threshold V

OV Low Threshold V

OV Voltage Reference Hysteresis V

OV Input Current I

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

GATEVGATE

GSCLMPVGATE

SENSE

UVLOHVDD

UVLOLVDD

UVH

UVL

UVHY

INUV

OVH

OVL

OVHY

INOV

Current into VDD with UV = 3V, OV, DRAIN, SENSE = V

GATE drive on, V

SENSE

VCL = V

SENSE

UV voltage increasing 1.240 1.255 1.270 V

UV voltage decreasing 1.105 1.125 1.145 V

UV = V

OV voltage rising 1.235 1.255 1.275 V

OV voltage decreasing 1.189 1.205 1.221 V

OV = V

, GATE = floating

= V

GATE

- VEE = 100mV, V

- VEE, steady state, 20V ≤ VDD ≤ 80V 10 13.5 18 V

- VEE, IGS = 30mA 15 16.4 18 V

- V

SENSE

= 50mV -1 -0.2 0 µA

increasing 13.8 15.4 17.0 V

decreasing 11.8 13.4 15.0 V

= 2V (Note 2) 24 50 70 mA

GATE

20 80 V

0.7 2 mA

-30 -45 -60 µA

40 50 60 mV

130 mV

-0.5 0 µA

50 mV

-0.5 0 µA

MAX5921/MAX5939

-48V Hot-Swap Controllers with External R

SENSE

and High Gate Pulldown Current

_______________________________________________________________________________________ 3

ELECTRICAL CHARACTERISTICS (continued)

(VEE= 0V, VDD= 48V, TA= -40°C to +85°C, unless otherwise noted. Typical values are at TA= +25°C, unless otherwise noted.) (Notes 1, 4)

)

Note 1: All currents into device pins are positive; all currents out of device pins are negative. All voltages are referenced to VEE,

unless otherwise specified.

Note 2: Gate pulldown current after the current limit to GATE low (t

PHLCL

) time has elapsed.

Note 3: Minimum duration of GATE pulldown following a circuit breaker fault. The MAX5921_ automatically restarts after a circuit

breaker fault. The MAX5939_ is latched off and can be reset by toggling UV low. The GATE pulldown does not release until t

OFF

has elapsed.

Note 4: The min/max limits are 100% production tested at +25°C and +85°C and guaranteed by design at -40°C.

PWRGD OUTPUT SIGNAL (REFERENCED TO DRAIN)

DRAIN Input Current I

DRAIN Threshold for PWRGD V

GATE High Threshold V PWRGD, PWRGD Output

Leakage

PWRGD Low Voltage (V

OVERTEMPERATURE PROTECTION

Overtemperature Threshold T

Overtemperature Hysteresis T

AC PARAMETERS

OV High to GATE Low t

UV Low to GATE Low t

OV Low to GATE High t

UV High to GATE High t

SENSE High to GATE Low t

Current Limit to GATE Low t

DRAIN Low to PWRGD Low DRAIN Low to (PWRGD - DRAIN) High

GATE High to PWRGD Low GATE High to (PWRGD - DRAIN) High

TURN-OFF

Latch-Off Period t

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

= 48V 10 80 250 µA

DRAIN

- VEE threshold for power-good

DRAIN

condition, DRAIN decreasing ∆V

- V

GATE

PWRGD

- V

DRAIN

(A, E versions)

= 5V, I

DRAIN

Junction temperature, temperature rising 135 °C

See Thermal Shutdown section 20 °C

Figures 1a, 2 0.5 µs

Figures 1a, 3 0.4 µs

Figures 1a, 2 3.3 µs

Figures 1a, 3 8.4 ms

Figures 1a, 4a 1 µs

Time from continuous current limit to GATE shutdown (see Overcurrent Fault Integrator section), Figures 1b, 4b

Figures 1a, 5a; A and E versions 8.2

Figures 1a, 5a; B and F versions 8.2

Figures 1a, 5b; A and E versions 8.2

Figures 1a, 5b; B and F versions 8.2

(Note 3) A, B, E, F versions

, decreasing 1.0 1.6 2.0 V

GATE

= 80V, V

< VDL, I

SINK

= 48V 10

DRAIN

= 0V 10

DRAIN

= 5mA

SINK

= 5mA (B, F versions) 0.11 0.4 V

A, B versions 0.35 0.5 0.65

E, F versions 1.4 2.0 2.6

1.1 1.7 2.0 V

0.11 0.4 V

128 x

PHLCL

PWRGD

- VEE)

- V

DRAIN

)

OT(TH

HYS

PHLOV

PHLUV

PLHOV

PLHUV

PHLSENSE

PHLCL

PHLDL

PHLGH

OFF

µA

MAX5921/MAX5939

-48V Hot-Swap Controllers with External R

SENSE

and High Gate Pulldown Current

4 _______________________________________________________________________________________

Typical Operating Characteristics

(VDD= +48V, VEE= 0V, TA = +25°C, unless otherwise noted.)

43.0

43.2

43.8

43.6

43.4

44.8

44.6

44.2

44.0

44.4

45.0

-40 10-15 356085

GATE PULLUP CURRENT

vs. TEMPERATURE

MAX5921TOC04

TEMPERATURE (°C)

GATE PULLUP CURRENT (µA)

GATE

= 0V

-40 10-15 356085

GATE PULLDOWN CURRENT

vs. TEMPERATURE AFTER A FAULT

MAX5921TOC05

TEMPERATURE (°C)

GATE PULLDOWN CURRENT (mA)

GATE

= 2V

04020 60 80 100

GATE PULLDOWN CURRENT

vs. OVERDRIVE DURING A CURRENT FAULT

MAX5921TOC06

OVERDRIVE (mV)

GATE PULLDOWN CURRENT (mA)

GATE

= 2V

100

400

300

200

500

600 900750 1050 1200

GATE PULLDOWN CURRENT

vs. OVERDRIVE DURING A SHORT CIRCUIT

MAX5921TOC07

OVERDRIVE (mV)

GATE PULLDOWN CURRENT (mV)

GATE

= 2V

160

120

140

100

180

-40 10-15 35 60 85

PWRGD OUTPUT LOW VOLTAGE vs. TEMPERATURE (MAX5921A)

MAX5921TOC08

TEMPERATURE (°C)

PWRGD OUTPUT LOW VOLTAGE (mV)

OUT

= 5mA

0.001

0.01

0.1

100

-40 10-15 35 60 85

PWRGD OUTPUT LEAKAGE CURRENT

vs. TEMPERATURE (MAX5921B)

MAX5921TOC09

TEMPERATURE (°C)

PWRGD OUTPUT LEAKAGE CURRENT (nA)

DRAIN

- VEE > 2.4V

200

100

500

400

300

800

700

600

900

04020 60 80 100

SUPPLY CURRENT

vs. SUPPLY VOLTAGE

MAX5921TOC01

SUPPLY VOLTAGE (V)

SUPPLY CURRENT (µA)

TA = +85°C

TA = +25°C

TA = -40°C

04020 60 80 100

GATE VOLTAGE

vs. SUPPLY VOLTAGE

MAX5921TOC02

SUPPLY VOLTAGE (V)

GATE VOLTAGE (V)

TA = +25°C

-40 10-15 356085

CURRENT-LIMIT TRIP VOLTAGE

vs. TEMPERATURE

MAX5921TOC03

TEMPERATURE (°C)

TRIP VOLTAGE (mV)

MAX5921/MAX5939

-48V Hot-Swap Controllers with External R

SENSE

and High Gate Pulldown Current

_______________________________________________________________________________________ 5

Figure 1a. Test Circuit 1

Figure 1b. Test Circuit 2

V+ 5V

5kΩ

PWRGD/PWRGD

MAX5921 MAX5939

DRAIN

GATE

SENSE

+48V

DRAIN

SENSE

+20V

PWRGD/PWRGD

DRAIN

+48V

10kΩ

MAX5921 MAX5939

GATE

SENSE

0.1µF

10Ω

IRF530

MAX5921/MAX5939

-48V Hot-Swap Controllers with External R

SENSE

and High Gate Pulldown Current

6 _______________________________________________________________________________________

Timing Diagrams

Figure 2. OV to GATE Timing

Figure 3. UV to GATE Timing

Figure 4a. SENSE to GATE Timing

Figure 4b. Active Current-Limit Threshold

1.255V

GATE

PHLOV

PLHOV

1.205V

1.125V

GATE

PHLUV

1.255V

PLHUV

SENSE

GATE

100mV

60mV

PHLSENSE

PHLCL

GATE

1V 1V

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