Philips Semiconductors Linear Products

Product specification

AM6012

12-Bit multiplying D/A converter

August 31, 1994

780

DIFFERENTIAL LINEARITY COMPARISON

Figure 1. Differential Linearity Comparison

±1/2LSB INL, ±1LSB DNL

±2LSB INL, ±1LSB DNL

0000 0010

0100 0110 1000 1010 1100 1110

0001 0011

0101 0111 1001 1011 1101 1111

IDEAL OUTPUTS

ACUTAL OUTPUTS

+1/2LSB

LIMIT

2LSB CHANGE ON

X011–X100

TRANSITION

SEGMENT

OF 12-BIT

DAC TRANSFER

CURVE FOR:

NO CHANGE ON

XX01–XX10 TRANSITION

–1/2LSB LIMIT

DIGITAL INPUT

INL =

±1/2LSB

DNL =

±1LSB

0010 0010

0100 0110 1000 1010 1100 1110

0001 0011

0101 0111 1001 1011 1101 1111

DNL =

±ℑ√2LSB

INL =

±2LSB

SEGMENT OF 12-BIT DAC

TRANSFER CURVE FOR:

–2 LSB

LIMIT

SEGMENT

CHANGE

IDEAL OUTPUTS

ACUTAL OUTPUTS

SEGMENT

CHANGE

+2LSB

LIMIT

DIGITAL INPUT

ANALOG OUTPUT CURRENTS

Both true and complemented output sink currents are provided

applied to each logic input. As the binary count increases, the sink

current at Pin 18 increases proportionally, in the fashion of a

“positive logic” D/A converter. When a “0” is applied to any input bit,

that current is turned off at Pin 18 and turned on at Pin 19. A

D/A converter. Both outputs may be used simultaneously. If one of

the outputs is not required, it must still be connected to ground or to

open.

Both outputs have an extremely wide voltage compliance enabling

fast direct current-to-voltage conversion through a resistor tied to

ground or other voltage source. Positive compliance is 25V above V-

and is independent of the positive supply. Negative compliance is

+10V above V-.

The dual outputs enable double the usual peak-to-peak load swing

when driving loads in quasi-differential fashion. This feature is

especially useful in cable driving, CRT deflection and in other

balanced applications such as driving center-tapped coils and

transformers.

POWER SUPPLIES

The AM6012 operates over a wide range of power supply voltages

from a total supply of 20V to 36V. When operating with V- supplies

operation decreases power consumption and increases negative

compliance, reference amplifier negative common-mode range,

negative logic input range, and negative logic threshold range;

consult the various figures for guidance. For example, operation at

compliance would be reduced to near zero. Operation from lower

supplies is possible, however at least 8V total must be applied to

insure turn-on of the internal bias network.

Symmetrical supplies are not required, as the AM6012 is quite

insensitive to variations in supply voltage. Battery operation is

feasible as no ground connection is required; however, an artificial

ground may be used to insure logic swings, etc., remain between

acceptable limits.

TEMPERATURE PERFORMANCE

The nonlinearity and monotonicity specifications of the AM6012 are

guaranteed to apply over the entire rated operating temperature

range. Full-scale output current drift is tight, typically

±10ppm/°C,

with zero-scale output current and drift essentially negligible

compared to 1/2LSB.

match and track that of the output resistor for minimum overall

full-scale drift.

SETTLING TIME

The AM6012 is capable of extremely fast settling times, typically

layout must be employed to obtain full performance potential during