HS-565BRH, HS-565BEH

4

FN4607.4

May 7, 2012

Power Supply Sensitivity

Power Supply Sensitivity is a measure of the change in gain and

offset of the D/A converter resulting from a change in -15V or

+15V supplies. It is specified under DC conditions and expressed

as parts per million of full scale range per percent of change in

power supply (ppm of FSR/%).

Compliance

Compliance Voltage is the maximum output voltage range that

can be tolerated and still maintain its specified accuracy.

Compliance Limit implies functional operation only and makes

no claims to accuracy.

Glitch

A glitch on the output of a D/A converter is a transient spike

resulting from unequal internal ON-OFF switching times. Worst

case glitches usually occur at half scale or the major carry code

transition from 011 . . . 1 to 100 . . . 0 or vice versa. For example,

if turn ON is greater than turn OFF for 011 . . . 1 to 100 . . . 0, an

intermediate state of 000 . . . 0 exists, such that, the output

momentarily glitches toward zero output. Matched switching

times and fast switching will reduce glitches considerably.

Applying the HS-565BRH and

HS-565BEH

OP AMP Selection

The HS-565BRH, HS-565BEH current output may be converted to

voltage using the standard connections shown in Figures 2 and 3.

The choice of operational amplifier should be reviewed for each

application, since a significant trade-off may be made between

speed and accuracy. Remember settling time for the

DAC-amplifier combination is:

No Trim Operation

The HS-565BRH, HS-565BEH will perform as specified without

calibration adjustments. To operate without calibration,

substitute 50Ω resistors for the 100Ω trimming

potentiometers: In Figure 2 replace R2 with 50Ω; also remove

the network on pin 8 and connect 50Ω to ground. For bipolar

operation in Figure 3, replace R3 and R4 with 50Ω resistors.

Typical unipolar zero will be ±0.50 LSB plus the op amp offset.

The feedback capacitor C must be selected to minimize settling

time.

Calibration

Calibration provides the maximum accuracy from a converter by

adjusting its gain and offset errors to zero. For the HS-565BRH,

HS-565BEH, these adjustments are similar whether the current

output is used, or whether an external op amp is added to

convert this current to a voltage. Refer to Table 1 for the voltage

output case, along with Figure 2 or 3.

Calibration is a two step process for each of the five output

ranges shown in Table 1. First adjust the negative full scale (zero

for unipolar ranges). This is an offset adjust which translates the

output characteristic, i.e., affects each code by the same

amount.

Next adjust positive FS. This is a gain error adjustment, which

rotates the output characteristic about the negative FS value.

For the bipolar ranges, this approach leaves an error at the zero

code, whose maximum values is the same as for integral

nonlinearity error. In general, only two values of output may be

calibrated exactly; all others must tolerate some error. Choosing

the extreme end points (plus and minus full scale) minimizes this

distributed error for all other codes.

t

D

t

A

+

VO

-

+

DAC

OUT

9

10

11

20V SPAN

10V SPAN

2.5k

5k

5k

C

9.95k

IO

24

13

MSB

LSB

. . . . .

CODE

INPUT

DAC

(4 x IREF

-VEE

PWR

GND

7

x CODE)

IREF

0.5mA

HS-565BRH

3k

3.5k

19.95k

+

-

10V

3

4

VCC

+

-

6

5

REF

GND

REF

IN

REF OUT

R2

100Ω

8

BIP.

OFF.

+15V

-15V

R1

50kΩ

100kΩ

100Ω

FIGURE 2. UNIPOLAR VOLTAGE OUTPUT

R (SEE

TABLE 1)

VO

-

+

DAC

OUT

9

10

11

20V SPAN

10V SPAN

2.5k

5k

5k

C

9.95k

IO

24

13

MSB

LSB

. . . . .

CODE

INPUT

DAC

(4 x IREF

-VEE

PWR

GND

7

x CODE)

IREF

0.5mA

HS-565BRH

3k

3.5k

19.95k

+

-

10V

3

4

VCC

+

-

6

5

REF

GND

REF

IN

REF OUT

R4

100Ω

8

BIP.

OFF.

R3

100Ω

FIGURE 3. BIPOLAR VOLTAGE OUTPUT

R (SEE

TABLE 1)