ML2340, ML2350

8

Bipolar Output Voltage Mode

GAIN 1

GAIN 0

GAIN

00

01

101

112

The output buffer can source or sink as much as 10mA of

current with an output voltage of at least 1V from either

AGND the current sourcing/sinking capability of the

output buffer is reduced. The output buffer can still swing

down to within 10mV of AGND and up to within 40mV of

operation. In the bipolar operation, the output buffer

swing is limited to about 100mV from either rails.

1.5 VOLTAGE REFERENCE

A bandgap voltage reference is incorporated on the ML2340

and ML2350. Two reference voltages can be produced by

each device. An internal comparator monitors the power

supply voltage to determine the selection of the reference

voltage. A reference voltage of 2.25 volts on the ML2340

and 2.50 volts on the ML2350 is selected when the supply

voltage is less than approximately 7.50 volts. Otherwise, a

reference voltage of 4.50 volts and 5.00 volts is selected. To

prevent the comparator from oscillating between the two

selections, avoid operation with a power supply between 70

and 8.0 volts.

The bandgap reference is trimmed for zero Temperature

Coefficient (TC) at 35°C to minimize output voltage drift

over the specified operating temperature range.

The internal reference is buffered for use by the DAC and

external circuits. The reference buffer will source more

than 5mA of current and sink more than 1mA of current.

voltage ranges of the DAC are obtained:

ML2340

Gain

Setting

Unipolar

Bipolar

Unipolar

Bipolar

0 to 0.562V –0.281V to

0 to 1.125V

–0.562V to

+0.281V

+0.562V

0 to 1.125V –0.562V to

0 to 2.250V

–1.125V to

+0.562V

+1.125V

1

0 to 2.250V –1.125V to

0 to 4.500V

–2.250V to

+1.125V

+2.250V

2

0 to 4.500V –2.250V to

0 to 9.000V

–4.500V to

+2.250V

+4.500V

ML2350

Gain

Setting

Unipolar

Bipolar

Unipolar

Bipolar

0 to 0.625V –0.3125V to

0 to 1.25V

–0.625V to

+0.3125V

+0.625V

0 to 1.250V –0.6250V to

0 to 2.50V

–1.250V to

+0.6250V

+1.250V

1

0 to 2.500V –1.2500V to

0 to 5.00V

–2.500V to

+1.2500V

+2.500V

2

0 to 5.000V –2.5000V to 0 to 10.00V

–5.000V to

+2.5000V

+5.000V

to set the desired full scale voltage. The linearity of the D/A

converter depends on the reference used, however. To

insure integral linearity at an 8-bit level, a reference

voltage of no less than 2V and no more than 7V (2.75V

for operation with a low-voltage power supply) should

be used.

1.6 DIGITAL INTERFACE

The digital interface of the ML2340 and ML2350 consist

of a transfer input (XFER) and eight data inputs, DB0

through DB7. The digital interface operates in one of the

two modes:

1.6.1 Single-Buffered Mode

Digital input data on DB0–DB7 is passed through an 8-bit

transparent input latch on the rising edge of XFER.

Because the outputs of the latch are connected directly to

the inputs of the internal DAC, changes on the digital data

while the XFER input is still active will cause an

immediate change in the DAC output voltage. To hold the

input data on the latch, the XFER input needs deactivated

while the data is still stable.

1.6.2 Flow-Through Mode

In the flow-through mode, the input latch is bypassed.

When XFER is set to logic “1”, a change of data inputs,

DB0–DB7, results in an immediate update of the output

voltage.

1.7 POWER-ON-RESET

The ML2340 and ML2350 have an internal power-on-

reset circuit to initialize the device when power is first

applied to the device. The power-on-reset interval of

approximately 2.0V. During the power-on-reset interval,

the transparent latch is reset to all “0’s”.