MAX4070

Features:

 Bidirectional, Compact, Current-Sense Solution
Total Output Error Less than 1.5%
Selectable Gain of 50V/V or 100V/V
Wide 1.35V to 24V Common-Mode Range
    Independent of Supply Voltage
2.7V to 24V Single-Supply Operation
Internal Precision Reference
    Adjustable (MAX4069)
    2.50V (MAX4070)
    1.50V (MAX4071)
Low 100A Supply Current
10A Supply Current in Shutdown
Available in Space-Saving Packages
    8-Pin Thin QFN (MAX4070/MAX4071/MAX4072)
    8-Pin MAX (MAX4070/MAX4071MAX4072)
    10-Pin MAX (MAX4069)


Application

Notebook Fuel Gauging
Smart-Battery Packs/Chargers
Motor Control
Power-Management Systems
Cell-Phone Battery-Current Monitoring


Pinout




Specifications

V_CC, RS+, RS- to GND ..............................................-0.3V to +26V
OUT to GND........................-0.3V to Lesser of (V_CC + 0.3V) or 15V
Differential Input Voltage (V_RS+ - V_RS-) ..............................±0.3V
GSEL, SHDN, REFOUT, REFIN
and ADJ to GND.............................................-0.3V to (V_CC + 0.3V)
OUT Short-Circuit Duration to GND
or to Lesser of (V_CC or 15V)........................................Continuous
REFOUT Short Circuit to V_CC or GND............................Continuous
Current into Any Pin ..........................................................±20mA
Continuous Power Dissipation (T_A = +70°C)
8-Pin MAX (derate 4.5 mW/°C above +70°C) ..................362mW
8-Pin Thin QFN (derate 24.4mW/°C above +70°C) .........1951mW
10-Pin MAX (derate 5.6 mW/°C above +70°C) .............444.4mW
Operating Temperature Range ..........................-40°C to +125°C
Junction Temperature.......................................................+150°C
Storage Temperature Range .............................-65°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C


Description

The MAX4070 low-cost, bidirectional, highside, current-sense amplifiers are ideal for monitoring battery charge and discharge currents in notebooks, cell phones, and other portable equipment. They feature up to 24V input common-mode voltage range, low 100A supply current (which drops to only 10A in shutdown), and a total output error of less than 1.5%. The wide 1.35V to 24V input common-mode range is independent of the supply voltage, ensuring that the current-sense feedback remains accurate even when connected to a battery pack in deep discharge.

To achieve maximum flexibility, an external current-sense resistor is used along with a Gain Select pin to choose either 50V/V or 100V/V. A single output pin continuously monitors the transition from charge to discharge and avoids the need for a separate polarity output. The MAX4070 contains an internal 2.5V reference. The charging current is represented by an output voltage from 2.5V to VCC, while discharge current is given from 2.5V to GND. The MAX4071 is similar, but with a reference voltage of 1.5V. The MAX4069 has an adjustable reference voltage, set by two external resistors. The MAX4072 has an input for an external reference.

The MAX4069/MAX4071/MAX4072 operate from a 2.7V to 24V single supply. The MAX4070 operates from a 3.6V to 24V single supply. All devices are specified over the automotive operating temperature range, -40°C to +125°C. The MAX4070/MAX4071/MAX4072 are available in 8-pin MAX and 8-pin thin QFN packages. The MAX4069 is available in a 10-pin MAX package.