Figure 5.11 dac loads – Sony Ericsson GR47/GR48 User Manual

Page 46

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5. SYSTEM CONNECTOR INTERFACE

46

LZT 123 7589 R1A

5.16.1 Digital to Analogue Converter - DAC

The DAC is an 8-bit converter. Conversion takes place when an AT
command is sent to the radio device. The radio device sends the resulting
analogue value to the DAC pin.

Tolerance on this internal voltage is ± 5 %

DAC output electrical characteristics are given in the following table.

(6)

Tolerance on this internal voltage is ± 5 %

(7)

Referred to the ideal conversion characteristic.

(8)

See Figure 5.11, page 46

Figure 5.11 DAC loads

Parameter

Limit

Units

Resolution

8

Bits

Output voltage for code = 0

(2.75

(6)

x 0.05) ± 0.05

V

Output voltage for code = 255

(2.75

(6)

x 0.95) ± 0.05

V

Nominal step size

(2.75

(6)

x 0.9)/256

mV

Absolute error

(7)

± 0.5

mV

Output wide-band noise and clock

feed-through 0 - 1.1 MHz

0.5

mV

rms

Power-supply rejection ratio 50 Hz - 10 kHz

40

dB

Conversion rate ± 0.5 LSB

2 (Load A)

(8)

ms

50 (Load B)

(8)

ms

Output buffer impedance when disabled

50

k

Output current source or sink

1

mA

Current consumption (active)

1.0

mA

1k

DGND

DAC

1nF

10nF

Load B

100k

DGND

DAC

100 - 200pF

Load A

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