PIN DESCRIPTION
Pin No.
1
2
3
Symbol
IB
CINT
V-
4
CAZ
5
BUF
6
AGND
7
C-REF
8
C+REF
9
N/C
10
N/C
11
V-REF
12
V+REF
13
V-IN
14
V+IN
15
A
16
B
17
COUT
18
DGND
19
V+
20
CS
Description
Bias circuit pin. Connect a 0.1µF capacitor from this pin to V- to minimize noise.
Integrator capacitor connection.
Negative power supply.
The Auto-zero capacitor connection.
The Integrator resistor buffer connection.
This pin is analog ground.
Negative reference capacitor connection.
Positive reference capacitor connection.
Internally connected. Connect to V- for normal operation.
Internally connected. Connect to V- for normal operation.
External voltage reference (-) connection. High impedance load (≥100MΩ) only.
External voltage reference (+) connection. High impedance load (≥100MΩ) only.
Negative analog input.
Positive analog input.
Converter phase control MSB Input.
Converter phase control LSB Input.
Comparator output. COUT is HIGH during the Integration phase when a positive input voltage is being integrated and
is LOW when a negative input voltage is being integrated. A HIGH-to-LOW transition on COUT signals the processor
that the Deintegrate phase is completed. COUT is undefined during the Auto-Zero phase. It should be monitored to
time the Integrator Zero phase.
Digital ground.
Positive power supply.
Chip select - power down pin. Logic 1 = power on. Logic 0 = power down.
Table 1. Conversion Phase and Control Logic Internal Analog Switch Functions
Conversion
Phase
Control
Logic
Input
Connect
SWIN
Reference Input
Polarity
SW+R or SW-R
Switch Functions
Auto Zero Reference VIN=AGND
Sample
SWAZ
SWR
SWG
System
Offset
SWS
Auto Zero
A = 0, B = 1
Open
Open
Closed
Closed
Input Signal
Integration
A = 1, B = 0 Closed
Open
Open
Open
Reference Voltage A = 1, B = 1
Deintegration
Open
Closed*
Open
Open
Integrator
Output Zero
A = 0, B = 0
Open
Open
Open
Closed
*SW+R would be closed for a positive input signal. SW-R would be closed for a negative input signal.
Closed
Open
Closed
Closed
Open
Open
Open
Closed
ALD500RAU/ALD500RA/ALD500R
Advanced Linear Devices
7