®
ADC-305
®
8-Bit, 20MHz CMOS A/D Converters
OBSOLETE PRODUCT
PRODUCT OVERVIEW
Contact Factory for Replacement Model and a wide 18MHz (–1dB)
sipation (60mW typical)
DATEL's ADC-305 is an 8-bit, 20MHz sampling, CMOS, subranging (two-pass) A/D converter.
It processes signals at speeds comparable to a full
flash converter by using a sub-ranging conversion
technique with multiple comparator blocks, each
containing a sample and hold amplifier.
The ADC-305 features CMOS low power disPin
1
FEATURES
■
input signal bandwidth.
The ADC-305-1 is packaged in 400 mil 24-pin DIP
and the ADC-305-3 in 300 mil 24-pin SOP.
Other features are CMOS compatible input logic,
3-state TTL compatible output logic, +5V single
power operation, self bias mode and low cost.
INPUT/OUTPUT CONNECTIONS
FUNCTION
Pin
OUTPUT ENABLE (OE)
24
FUNCTION
DGND
8-bit resolution, 20MHz min. sampling rate
2
DGND
23
REF. BOTTOM (VRB)
■
±½LSB max. differential nonlinearity error
3
BIT 8 (LSB)
22
SELF BIAS 1 (VRBS)
■
18MHz input signal bandwidth
4
BIT 7
21
AGND
5
BIT 6
20
AGND
■
Subranging, S&H enclosed
6
BIT 5
19
ANALOG INPUT (VIN)
■
+5V single power, low 85mW max. dissipation
7
BIT 4
18
+AVS (+5V)
8
BIT 3
17
REFERENCE TOP (VRT)
■
CMOS compatible logic input
■
3-State TTL compatible output
9
BIT 2
16
SELF BIAS 2 (VRTS)
10
BIT 1 (MSB)
15
+AVS (+5V)
11
+DVS (+5V)
14
+AVS (+5V)
12
CLOCK INPUT (A/D CLK)
13
+DVS (+5V)
Both the ADC-305-1 and the ADC-305-3 have the same pin assignment.
24 DGND
OUTPUT ENABLE 1
REFERENCE
VOLTAGE
DGND 2
23 VRB
22 VRBS
BIT 8 (LSB) 3
BIT 7 4
BIT 6 5
LOWER
DATA
LATCHES
LOWER
ENCODER
(4 BIT)
21 AGND
B BLOCK
COMPARATORS
WITH S/H (4 BIT)
20 AGND
19 VIN
BIT 5 6
BIT 4 7
BIT 3 8
BIT 2 9
UPPER
DATA
LATCHES
BIT 1 (MSB) 10
LOWER
ENCODER
(4 BIT)
UPPER
ENCODER
(4 BIT)
18 +AVS
A BLOCK
COMPARATORS
WITH S/H (4 BIT)
UPPER
COMPARATORS
WITH S/H (4 BIT)
17 VRT
16 VRTS
15 +AVS
+DVS 11
A/D CLK 12
CLOCK
GENERATOR
14 +AVS
13 +DVS
Figure 1. Functional Block Diagram
DATEL
•
11 Cabot Boulevard, Mansfield, MA 02048-1151 USA
•
Tel: (508) 339-3000
•
www.datel.com
30 Mar 2011
•
e-mail: help@datel.com
MDA_ADC-305.B02 Page 1 of 6
