MAX4004 Просмотр технического описания (PDF) - Maxim Integrated

Номер в каталоге

Компоненты Описание

производитель

MAX4004

High-Accuracy, High-Side Current Monitors in SOT23

Maxim Integrated 

MAX4004/MAX4006

Functional Diagrams

BIAS

MAX4004

CURRENT

MONITOR

10x

1x

CURRENT

CLAMP

REF

GND

CLAMP

OUT

High-Accuracy, High-Side Current Monitors

in SOT23

BIAS

MAX4006

CURRENT

MONITOR

10x

1x

CURRENT

CLAMP

REF

CLAMP

OUT

10kΩ

GND

Detailed Description

The MAX4004/MAX4006 are versatile current monitors

intended for monitoring DC photodiode current in fiber

applications (see the Functional Diagram). The MAX4004

output is a current that is exactly one-tenth of the refer-

ence current. The MAX4006 outputs a voltage that is pro-

portional to the reference current with a transimpedance

gain of 1V/mA achieved by a factory-trimmed, internal

10kΩ resistor.

Both current devices have six decades of dynamic range

and monitor reference current ranging from 250nA to

2.5mA, the nominal operating range, with better than

5% accuracy across the entire reference current, bias

voltage, and temperature ranges. The corresponding

monitor outputs produce 25nA to 0.25mA (MAX4004) and

0.25mV to 2.5V (MAX4006). When the reference currents

are extended to the broader range of 10nA to 10mA, an

accuracy of less than 10% is maintained. Internal current

limiting (20mA, typ) protects the device against short-

circuit-to-ground conditions, and a thermal shutdown fea-

ture reduces both the reference current and the monitor

current to zero if the die temperature reaches +150°C.

The MAX4004/MAX4006 accept a +2.7V to +22V sup-

ply voltage, suitable for PIN photodiode applications.

A clamping diode, shown in the Functional Diagram, is

provided to protect subsequent output circuitry from an

overvoltage condition.

Applications Information

Clamping the Monitor Output Voltage

CLAMP provides a means for diode clamping the voltage

at OUT, thus VOUT is limited to VCLAMP + 0.6V. CLAMP

can be connected to either an external supply, to BIAS,

or can be left floating if voltage clamping is not required.

Using PIN Photodiodes in Fiber

Applications

When using the MAX4004/MAX4006 to monitor PIN

photodiode currents in fiber applications, several issues

must be addressed. In applications where the photodiode

must be fully depleted, keep track of voltages budgeted

for each component with respect to the available supply

voltage(s). The current monitor requires as much as 1.2V

between BIAS and REF, which must be considered as

part of the overall voltage budget.

Additional voltage margin can be created if a negative

supply is used in place of a ground connection, as long

as the overall voltage drop experienced by the MAX4004/

MAX4006 is less than or equal to 22V. For this type of

application, the MAX4004 is suggested so the output can

be referenced to “true” ground and not the negative sup-

ply. The MAX4004’s output current can be referenced as

desired with either a resistor to ground or a transimped-

ance amplifier. Take care to ensure that output voltage

excursions do not interfere with the required margin

between BIAS and OUT.

www.maximintegrated.com

Maxim Integrated │  7

Share Link: