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MAX34406

Quad Current-Sense Amplifier

with Overcurrent Threshold Comparators

�� Maxim Integrated Products 1

General Description

The MAX34406 is a quad, high-side, unidirectional, cur-

rent-sense amplifier that offers precision accuracy. It

provides analog outputs for each of the four amplifiers

that can be routed to an external ADC, and contains four

overcurrent comparators with a fixed 1.0V threshold. All

four comparators are logically ORed, and the result can

be delayed/filtered with an external capacitor before it is

fed to a latched common shutdown open-drain output pin.

Applications

Network Switches/Routers

Base Stations

Servers

Smart Grid Network Systems

Industrial Controls

Features

S Four Precision Current-Sense Amplifiers

S Fixed Gains of 25V/V, 50V/V, 100V/V, and 200V/V

S Less Than ±600µV of Input Offset

S Less Than ±0.6% of Gain Error (T/F/H) or ±0.8% of

Gain Error (W)

S Wide 2.0V to 28V Common Mode Range

S Analog Voltage Outputs for Each Amplifier

S Independent Overcurrent Comparators with Fixed

1.0V Threshold

S Low Power Consumption

S -40NC to +85NC Temperature Range

S Small 24-Pin TQFN (4mm x 4mm) Package

Block Diagram

19-5930; Rev 1; 1/12

Ordering Information appears at end of data sheet.

For related parts and recommended products to use with this part, refer to: www.maxim-ic.com/MAX34406.related

EVALUATION KIT AVAILABLE

AMPLIFIER 4

DD ENA

CDLYOCxGNDOUTx

INx+

INx-

SHTDN

AMPLIFIER 3

AMPLIFIER 2

AMPLIFIER 1

MAX34406

OUT

CLAMP

5µA

POR

1.0V

REFERENCE

CLR

LATCH THRESHOLD = V

x 50%

4 4

For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,

or visit Maxim’s website at www.maxim-ic.com.

Summary of content (11 pages)

PAGE 1
9-5930; Rev 1; 1/12 EVALUATION KIT AVAILABLE MAX34406 Quad Current-Sense Amplifier with Overcurrent Threshold Comparators General Description The MAX34406 is a quad, high-side, unidirectional, current-sense amplifier that offers precision accuracy. It provides analog outputs for each of the four amplifiers that can be routed to an external ADC, and contains four overcurrent comparators with a fixed 1.0V threshold.
PAGE 2
MAX34406 Quad Current-Sense Amplifier with Overcurrent Threshold Comparators ABSOLUTE MAXIMUM RATINGS Voltage Range on INx+ and INxRelative to GND..................................................-0.3V to +30V Voltage Range on VDD Relative to GND..................-0.3V to +6V Voltage Range on Remaining Pins Relative to GND..................................... -0.3V to (VDD + 0.3V) Continuous Power Dissipation (TA = +70NC) TQFN (derate 27.8mW/NC above +70NC)...............2222.
PAGE 3
MAX34406 Quad Current-Sense Amplifier with Overcurrent Threshold Comparators ELECTRICAL CHARACTERISTICS (continued) (VINx+ = VINx- = 12V, VSENSE = 0V, TA = -40NC to +85NC, unless otherwise noted. Typical values are TA = +25NC) (Note 1)x PARAMETER SYMBOL Output Leakage (SHTDN, OCx) CONDITIONS MIN TYP IO Comparator Threshold VTH 0.98 1.00 MAX UNITS Q1 FA 1.
PAGE 4
MAX34406 Quad Current-Sense Amplifier with Overcurrent Threshold Comparators Typical Operating Characteristics (continued) ((VINx+ = VINx- = 12V, TA = +25°C, unless otherwise noted.) INPUT OFFSET vs. COMMON-MODE VOLTAGE 0 -10 -20 -20 -30 -40 5 10 15 20 25 0.2 0.1 -0.1 -60 30 -40 -15 10 35 60 0 85 5 10 15 20 25 COMMON-MODE VOLTAGE (V) TEMPERATURE (°C) COMMON-MODE VOLTAGE (V) GAIN ERROR vs. TEMPERATURE SMALL-SIGNAL GAIN vs.
PAGE 5
MAX34406 Quad Current-Sense Amplifier with Overcurrent Threshold Comparators IN4- OUT4 OUT3 IN3- IN3+ TOP VIEW IN4+ Pin Configuration 18 17 16 15 14 13 VDD 19 12 OC4 ENA 20 11 OC3 10 OC2 9 OC1 8 N.C. 7 N.C. SHTDN 21 MAX34406 CDLY 22 N.C. 23 EP + 1 2 3 4 5 6 IN1+ IN1- OUT1 OUT2 IN2- IN2+ GND 24 TQFN (4mm x 4mm) Pin Description PIN NAME FUNCTION 1 IN1+ External Sense Resistor Power-Side Connection for Amplifier 1.
PAGE 6
MAX34406 Quad Current-Sense Amplifier with Overcurrent Threshold Comparators Pin Description (continued) PIN NAME FUNCTION 14 IN3- 15 OUT3 External Sense Resistor Load-Side Connection for Amplifier 3 16 OUT4 17 IN4- External Sense Resistor Load-Side Connection for Amplifier 4 18 IN4+ External Sense Resistor Power-Side Connection for Amplifier 4. Bias at this pin also provides the supply voltage for amplifier 4. This pin can be left open circuit if not needed.
PAGE 7
MAX34406 Quad Current-Sense Amplifier with Overcurrent Threshold Comparators Typical Application Circuit V1 VDD IN1+ VDD RSENSE1 GND IN1ENA VDD V2 IN2+ RPU RSENSE2 SHTDN IN2- VDD MAX34406 V3 RPU IN3+ OC1 RSENSE3 OC2 IN3- µC OC3 OC4 OUT1 V4 IN4+ OUT2 ADC INPUTS OUT3 OUT4 RSENSE4 IN4- CDLY CCDLY �� Maxim Integrated Products 7
PAGE 8
MAX34406 Quad Current-Sense Amplifier with Overcurrent Threshold Comparators Detailed Description The MAX34406 quad-channel, unidirectional, high-side, current-sense amplifier features a 2.0V to 28V input common-mode range. This feature allows the monitoring of current out of a voltage supply as low as 2.0V. The device monitors current through a current-sense resistor and amplifies the voltage across that resistor. Current-sense amplifier output voltages (OUT1 to OUT4) are compared to a fixed 1.
PAGE 9
MAX34406 Quad Current-Sense Amplifier with Overcurrent Threshold Comparators Efficiency and Power Dissipation At high current levels, the I2R losses in RSENSE can be significant. Take this into consideration when choosing the resistor value and its power dissipation (wattage) rating. Also, the sense resistor’s value might drift if it is allowed to heat up excessively. The precision VOS of the device allows the use of small sense resistors to reduce power dissipation and reduce hot spots.
PAGE 10
MAX34406 Quad Current-Sense Amplifier with Overcurrent Threshold Comparators RIN x IBIAS contributes to the input voltage offset. IBIAS is typically 0.2FA. Placing RIN at the INx- input voltage does not affect the gain error of the device because the gain is given by the ratio between ROUTx and R1 at INx+. Bidirectional Application Some systems can require a precise bidirectional current-sense amplifier to accurately monitor currents.
PAGE 11
MAX34406 Quad Current-Sense Amplifier with Overcurrent Threshold Comparators Revision History REVISION NUMBER REVISION DATE 0 6/11 Initial release 1/12 Removed the requirement for the bleed resistor on CDLY; added the function to discharge the CDLY capacitor when all four OCx outputs are low (Block Diagram, Electrical Characteristics table tDLY specification, Pin Description, Typical Application Circuit, and Choosing the Delay Capacitor section) 1 DESCRIPTION PAGES CHANGED — 1, 3, 6, 7, 10 Maxim