adc-228a Murata Manufacturing Co., Ltd, adc-228a Datasheet - Page 3

• Manufacturer Part Number: adc-228a
• Description: 8-bit, 20mhz, Complete Flash A/d Converter
• Manufacturer: Murata Manufacturing Co., Ltd

TECHNICAL NOTES
1. Rated performance requires using good high-frequency techniques. The analog and digital
ground pins are connected to each other internally. Avoid ground related problems by connecting
the grounds to one point, the ground plane beneath the converter. Due to the inductance and
resistance of the power supply return paths, return the analog and digital ground separately to the
power supplies.
2. Bypass all the analog and digital supplies and the +5V REFERENCE (pin 3) to ground with a
4.7µF, 25V tantalum electrolytic capacitor in parallel with a 0.1µF ceramic capacitor.
ANALOG INPUT
+4.96V
+3.75V
+2.50V
+1.25V
+0.02V
0.00V
Table 1. ADC-228A Unipolar Output Coding
+FS – 1 LSB
+ 3/4 FS
+ 1/2 FS
+ 1/4 FS
+ 1 LSB
CODE
ZERO
OUTPUT
DIGITAL
CLOCK
ANALOG
* Use optional resistor only if
amp is not used to drive input.
INPUT
R = V
EE
/1.667mA
STRAIGHT BIN.
51 Ω
1111 1110
1100 0000
1000 0000
0100 0000
0000 0001
0000 0000
www.murata-ps.com
HOLD TIME
OUTPUT
CLOCK 18
SAMPLE
9k Ω
*Optional
CS1 11
CS1 12
N
V
4.7μF
IN
5
Figure 3. ADC-228A Typical Connections
Figure 2. ADC-228A Timing Diagram
+
0.1μF
DATA
N
+15V
+
+5V
19
4.7μF
1
0.1μF
SAMPLE
OUTPUT
N + 1
ADC-228A
DELAY
–15V
2, 4, 6, 7
10
DATA
Pin 12
N + 1
CS2
0.1μF
8-Bit, 20MHz, Complete Flash A/D Converter
0
0
1
1
Table 2. Chip Select Truth Table
4.7μF
4.7μF
Pin 11
CS1
Technical enquiries email: [e-mail], tel:
SAMPLE
0
1
0
1
8, 9, 13, 20
N + 2
14
15
16
17
21
22
23
24
+
3
+
B1 (MSB)
B2
B3
B4
B5
B6
B7
B8 (LSB)
Three State Mode
Three State Mode
Three State Mode
0.1μF
Data Outputted
+5V REFERENCE OUT
NO CONNECTION
DATA
N + 2
Bits 1-8
MDA_ADC-228A.B01 Page 3 of 4
ADC-228A
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