ADC0808S125/250
Single 8-bit ADC, up to 125 MHz or 250 MHz
Rev. 03 — 24 February 2009
Product data sheet
1. General description
The ADC0808S is a differential, high-speed, 8-bit Analog-to-Digital Converter (ADC)
optimized for telecommunication transmission control systems and tape drive
applications. It allows signal sampling frequencies up to 250 MHz.
The ADC0808S clock inputs are selectable between 1.8 V Complementary Metal Oxide
Semiconductor (CMOS) or Low-Voltage Differential Signals (LVDS). The data output
signal levels are 1.8 V CMOS.
All static digital inputs (CLKSEL, CCSSEL, CE_N, OTC, DEL0 and DEL1) are 1.8 V
CMOS compatible.
The ADC0808S offers the most flexible acquisition control system possible due to its
programmable Complete Conversion Signal (CCS) which allows the delay time of the
acquisition clock and acquisition clock frequency to be adjusted.
The ADC0808S is supplied in an HTQFP48 package.
2. Features
I
I
I
I
I
I
I
I
I
I
I
I
I
I
8-bit resolution
High-speed sampling rate up to 250 MHz
Maximum analog input frequency up to 560 MHz
Programmable acquisition output clock (complete conversion signal)
Differential analog input
Integrated voltage regulator or external control for analog input full-scale
Integrated voltage regulator for input common-mode reference
Selectable 1.8 V CMOS or LVDS clock input
1.8 V CMOS digital outputs
1.8 V CMOS compatible static digital inputs
Binary or 2’s complement CMOS outputs
Only 2 clock cycles latency
Industrial temperature range from
−40 °C
to +85
°C
HTQFP48 package
3. Applications
I
2.5G and 3G cellular base infrastructure radio transceivers
I
Wireless access systems
I
Fixed telecommunications
NXP Semiconductors
ADC0808S125/250
Single 8-bit ADC, up to 125 MHz or 250 MHz
I
Optical networking
I
Wireless Local Area Network (WLAN) infrastructure
I
Tape drive applications
4. Ordering information
Table 1.
Ordering information
Sampling frequency Package
(MHz)
Name
125
250
Description
Version
Type number
ADC0808S125HW/C1
ADC0808S250HW/C1
HTQFP48 plastic thermal enhanced thin quad flat package; SOT545-2
48 leads; body 7
×
7
×
1 mm; exposed die pad
5. Block diagram
CLKSEL
36
CLK+ CLK−
37
38
39
40
DEL0
DEL1
CLOCK DRIVER
ADC0808S
LATCH
17
26
CCS
CCSSEL
IN
INN
33
32
TRACK
AND
HOLD
8
RESISTOR
LADDERS
ADC
CORE
LATCH
8
D0 to D7
21
OTC
FSIN/
REFSEL
30
U/I
LATCH
20
IR
INTERNAL
REFERENCE
CMADC
REFERENCE
29
CMADC
OUTPUTS
ENABLE
19
001aai267
CE_N
Fig 1.
Block diagram
ADC0808S125_ADC0808S250_3
© NXP B.V. 2009. All rights reserved.
Product data sheet
Rev. 03 — 24 February 2009
2 of 23
NXP Semiconductors
ADC0808S125/250
Single 8-bit ADC, up to 125 MHz or 250 MHz
6. Pinning information
6.1 Pinning
43 V
CCO4(1V8)
46 OGND4
OGND1
D3
i.c.
V
CCO1(1V8)
D4
i.c.
OGND2
D5
i.c.
1
2
3
4
5
6
7
8
9
DGND
37 CLK+
36 CLKSEL
35 i.c.
34 V
CCA1(3V3)
33 IN
32 INN
31 AGND2
30 FSIN/REFSEL
29 CMADC
28 AGND1
27 NC1V8
26 CCSSEL
25 n.c.
n.c. 24
001aai268
40 DEL1
OTC 21
39 DEL0
DGND1 22
ADC0808S
V
CCO2(1V8)
10
D6 11
i.c. 12
V
CCO3(1V8)
13
D7 14
i.c. 15
OGND3 16
CCS 17
i.c. 18
CE_N 19
IR 20
Fig 2.
Pin configuration
6.2 Pin description
Table 2.
Symbol
OGND1
D3
i.c.
V
CCO1(1V8)
D4
i.c.
OGND2
D5
i.c.
V
CCO2(1V8)
D6
i.c.
V
CCO3(1V8)
D7
ADC0808S125_ADC0808S250_3
Pin description
Pin
1
2
3
4
5
6
7
8
9
10
11
12
13
14
Type
[1]
G
O
-
P
O
-
G
O
-
P
O
-
P
O
Description
data output ground 1
data output bit 3
internally connected; leave open
data output supply voltage 1 (1.8 V)
data output bit 4
internally connected; leave open
data output ground 2
data output bit 5
internally connected; leave open
data output supply voltage 2 (1.8 V)
data output bit 6
internally connected; leave open
data output supply voltage 3 (1.8 V)
data output bit 7
© NXP B.V. 2009. All rights reserved.
Product data sheet
Rev. 03 — 24 February 2009
V
CCD1(1V8)
23
38 CLK−
41 D0
42 i.c.
48 i.c.
45 i.c.
47 D2
44 D1
3 of 23
NXP Semiconductors
ADC0808S125/250
Single 8-bit ADC, up to 125 MHz or 250 MHz
Pin description
…continued
Pin
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
-
Type
[1]
-
G
O
-
I(CMOS)
O(CMOS)
I(CMOS)
G
P
-
-
I(CMOS)
I
G
O
I
G
I
I
P
-
I(CMOS)
I
I
I(CMOS)
I(CMOS)
O
-
P
O
-
G
O
-
G
Description
internally connected; leave open
data output ground 3
complete conversion signal output
internally connected; leave open
chip enable input (active LOW)
in-range output
control input for 2’s complement output
digital ground 1
digital supply voltage 1 (1.8 V)
not connected
not connected
control input for CCS frequency selection
not connected or connected to V
CCD1(1V8)
analog ground 1
regulator common-mode ADC output
full-scale reference voltage input/internal or external
reference selection
analog ground 2
complementary analog input
analog input
analog supply voltage 1 (3.3 V)
internally connected; leave open
control input for clock input selection
clock input
complementary clock input
complete conversion signal delay input 0
complete conversion signal delay input 1
data output bit 0
internally connected; leave open
data output supply voltage 4 (1.8 V)
data output bit 1
internally connected; leave open
data output ground 4
data output bit 2
internally connected; leave open
digital ground; exposed die pad
Table 2.
Symbol
i.c.
OGND3
CCS
i.c.
CE_N
IR
OTC
DGND1
V
CCD1(1V8)
n.c.
n.c.
CCSSEL
NC1V8
AGND1
CMADC
FSIN/REFSEL
AGND2
INN
IN
V
CCA1(3V3)
i.c.
CLKSEL
CLK+
CLK−
DEL0
DEL1
D0
i.c.
V
CCO4(1V8)
D1
i.c.
OGND4
D2
i.c.
DGND
[1]
See
Table 3.
ADC0808S125_ADC0808S250_3
© NXP B.V. 2009. All rights reserved.
Product data sheet
Rev. 03 — 24 February 2009
4 of 23
NXP Semiconductors
ADC0808S125/250
Single 8-bit ADC, up to 125 MHz or 250 MHz
Pin type description
Description
input
output
1.8 V CMOS level input
1.8 V CMOS level output
power supply
ground
Table 3.
Type
I
O
I(CMOS)
O(CMOS)
P
G
7. Functional description
7.1 CMOS/LVDS clock input
The circuit has two clock inputs CLK+ and CLK−, with two modes of operation:
•
LVDS mode: CLK+ and CLK− inputs are at differential LVDS levels. An external
resistor of between 80
Ω
and 120
Ω
is required; see
Figure 3.
maximum V
idth
V
O(dif)
undefined state
minimum V
idth
LVDS
DRIVER
RECEIVER
CLK+
CLK−
V
gpd
001aah720
Fig 3. LVDS clock input
•
1.8 V CMOS mode: CLK+ input is at 1.8 V CMOS level and sampling is done on the
rising edge of the clock input signal. In this case pin CLK− must be grounded;
see
Figure 4.
CMOS
DRIVER
CLK+
CLK−
001aai272
Fig 4. CMOS clock input
ADC0808S125_ADC0808S250_3
© NXP B.V. 2009. All rights reserved.
Product data sheet
Rev. 03 — 24 February 2009
5 of 23
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