AS1536-BSOT Ver la hoja de datos (PDF) - austriamicrosystems AG

Número de pieza

componentes Descripción

Fabricante

AS1536-BSOT

12-Bit, Single Supply, Low-Power, 73ksps A/D Converters

austriamicrosystems AG 

AS1536/AS1537

Datasheet - Detailed Description

Transfer Function

The data output from the AS1536/AS1537 is binary (unipolar), and Figure 28 depicts the nominal transfer function.

Code transitions occur midway between successive integer LSB values.

Note: If VREF = +2.50V, then 1 LSB = 610µV (2.50V/4096).

Figure 28. Unipolar Transfer Function

11...111

11...1110

11....101

Full Scale (FS)

Transition

Full Scale = VREF

Zero Scale = 0

1LSB = VREF/4096

00...011

00...010

00...001

00...000

0

12

3

FS - 3/2LSB

Input Voltage AIN

Reducing Supply Current

Power consumption can be reduced significantly by powering down the devices between conversions. Figure 30

shows a plot of an average supply current versus sampling rate.

Wake-up time (tWAKE) can also factor into reduced power consumption. tWAKE is defined as the time from when pin

SHDNN is deasserted to the time when a conversion may be initiated (see Figure 29).

Figure 29. Shutdown Sequence Timing Diagram

CSN

SHDNN

DOUT

Complete Conversion Sequence

tWAKE

Conversion 0

Power-Up

Shutdown

Conversion 1

Power-Up

For the AS1536 using the internal reference, tWAKE depends on the time in shutdown mode (see Figure 31) since the

external 4.7µF reference bypass capacitor slowly loses charge during shutdown. The wakeup time for AS1536 and

AS1537 using an internal reference are largely dependent on the external reference’s power-up time. The wakeup time

for the ADC itself from shutdown mode is approximately 4µs.

www.austriamicrosystems.com

Revision 1.01

15 - 22

Share Link: