FAIRCHILD SPT8100

SPT8100
16-BIT, 5 MSPS CMOS A/D CONVERTER
TECHNICAL DATA
JANUARY 9, 2002
FEATURES
APPLICATIONS
• 16-bit, 5 MSPS CMOS analog-to-digital converter
• On-chip PGA: gain range from 0 to 19.5 dB in seven
selectable settings:
0 dB, +2.9 dB, +5.8 dB, +11.8 dB, +14.8 dB, +17.5 dB,
+19.5 dB
• DLE: ±0.5 LSB, ILE: ±1.25 LSB
• SFDR: 94 dB @ ƒIN = 900 kHz, –8.1 dBFS
• Internal sample-and-hold and voltage reference
• Power dissipation: 465 mW at 5 MSPS
• +5 V analog supply and +3.3 to +5.25 V digital output
supply
• 44-lead LQFP plastic package
•
•
•
•
•
•
•
•
Data acquisition systems
IR imaging
Scanners and digital copiers
High-end CCD cameras
Medical imaging
Wireless communications
Lab and test equipment
Automatic test equipment
DESCRIPTION
The SPT8100 is a high-performance, 16-bit analog-todigital converter that operates at a sample rate of up to
5 MSPS. Excellent dynamic performance and high linearity is achieved by a digitally calibrated pipelined architecture fabricated in CMOS process technology.
A low-noise programmable gain amplifier (PGA) is also incorporated on chip. The PGA is digitally programmable in
seven selected settings over a 0 to +19.5 dB range. The
BLOCK DIAGRAM
AVDD
+5V
SPT8100 also features an on-chip internal sample-andhold and internal reference for minimal external circuitry.
It operates from a single +5 V supply. Total power dissipation, including internal reference, is 465 mW. A separate
digital output supply pin is provided for +3.3 V or 5 V logic
output levels. The SPT8100 is available in a 44-lead LQFP
package over the industrial temperature range of –40 °C to
+85 °C.
DVDD
+5V
OVDD
+3/5 V
OE (Output Enable)
Low-Noise
PGA
OVR (Over-Range)
VIN+
16-bit, 5 MSPS ADC
VIN–
16-bits
D15 – D0
(Data Outputs)
VCM
GS2 – GS0
(Gain Set)
RS (Reset)
VREF
AGND DGND OGND BIASC
(Ext Bias
Capacitor)
BIASR
(Ext Bias
Resistor)
RDY (Ready)
VRT
VRB
CLK
ABSOLUTE MAXIMUM RATINGS (Beyond which damage may occur)1 25 °C
Supply Voltages
AVDD ...................................................................... +6 V
DVDD ..................................................................... +6 V
OVDD ..................................................................... +6 V
Input Voltages
Analog Input ................................. –0.5 V to VDD +0.5 V
CLK Input ............................................................... VDD
AVDD – DVDD .................................................. ±100 mV
Delta between AGND, DGND, and OGND ...... ±100 mV
Output
Digital Outputs .................................................... 10 mA
Temperature
Operating Temperature ........................... –40 to +85 °C
Junction Temperature ...................................... +175 °C
Lead Temperature (soldering 10 seconds) ...... +300 °C
Storage Temperature ............................ –65 to +150 °C
Note 1: Operation at any Absolute Maximum Rating is not implied. See
Electrical Specifications for proper nominal applied conditions in
typical applications.
ELECTRICAL SPECIFICATIONS
TA=TMIN to TMAX, AVDD=DVDD=+5.0 V, OVDD= 3.3 V, ƒS=5 MSPS, 2.5 VPP input span, Gain=0 dB, REXT=1.43 kΩ, unless
otherwise specified.
PARAMETERS
TEST
CONDITIONS
TEST
LEVEL
Resolution
DC Accuracy
Integral Linearity Error (ILE)
Differential Linearity Error (DLE)
Gain Error1
Offset Error2
V
V
IV
IV
Analog Input (into PGA)
Differential Input Voltage Range
VIN+, VIN–
Input Capacitance
PGA Gain = 0 dB
Input Resistance3
Input Bandwidth4
PGA Gain = 0 dB
Input Common Mode Voltage Range
V
IV
IV
V
V
Programmable Gain Amp
Composite Input-Referred
Noise Floor
ƒIN > 300 kHz
PGA Gain = 0 dB
PGA Gain = 2.9 dB
PGA Gain = 5.8 dB
PGA Gain = 11.8 dB
PGA Gain = 14.8 dB
PGA Gain = 17.5 dB
PGA Gain = 19.5 dB
PGA Range
PGA Gain Steps3
PGA Gain Accuracy
Conversion Characteristics
Maximum Conversion Rate
Pipeline Delay (Latency)5
Reset Pulse Time (RS)
Reset Calibration Time
FS = 5 MSPS
References and External Bias
VRT – VRB (Internal Ref)
Bias Resistor Range (External)
VCM Output Voltage
VCM Output Current
VRT
VRB
Total gain error of PGA and ADC using internal references.
Total offset error of PGA and ADC relative to mid-scale.
3 See table I for input resistance as a function of PGA gain.
1
4
2
5
MIN
SPT8100
TYP
15.9
16
MAX
Bits
±1.25
±0.5
–7.5
–5
+7.5
+5
5
15
1.15
5.5
12
2.40
UNITS
3.65
LSB
LSB
%FSR
%FSR
VPPD
pF
kΩ
MHz
V
V
V
V
V
V
V
V
V
VI
VI
1.4
1.5
1.6
2.0
2.3
2.6
2.8
19.5
0,2.9,5.8,11.8,14.8,17.5,19.5
±0.3
LSBRMS
LSBRMS
LSBRMS
LSBRMS
LSBRMS
LSBRMS
LSBRMS
dB
dB
dB
VI
IV
IV
V
5
MSPS
Clocks
Clocks
ms
VI
V
IV
IV
V
V
2.375
800
2.275
2.5
1430
2.40
3.45
0.95
3.65
1.15
5.5
3
150
2.625
2500
2.525
47
3.85
1.35
V
Ω
V
µA
V
V
Input bandwidth is a frequency to which the fundamental energy drops by 3 dB
The input is sampled on the falling edge of the clock and is available on the
output after the rising edge of the clock, 5.5 clock cycles later.
SPT8100
2
1/9/02
ELECTRICAL SPECIFICATIONS
TA=TMIN to TMAX, AVDD=DVDD=+5.0 V, OVDD= 3.3 V, ƒS=5 MSPS, 2.5 VPP input span, Gain=0 dB, REXT=1.43 kΩ, unless
otherwise specified.
PARAMETERS
Dynamic Performance1
Effective Number of Bits
ƒIN = 60 kHz
ƒIN = 900 kHz
Signal-to-Noise Ratio
(without Harmonics)
ƒIN = 75 kHz
ƒIN = 900 kHz
Harmonic Distortion
ƒIN = 60 kHz
ƒIN = 900 kHz
Signal-to-Noise and Distortion
(SINAD)
ƒIN = 60 kHz
ƒIN = 900 kHz
Spurious Free Dynamic Range3
ƒIN = 60 kHz
ƒIN = 900 kHz
ƒIN = 2 MHz
ƒIN = 3 MHz
Two-Tone Intermodulation
3rd Order Distortion
TEST
CONDITIONS
TEST
LEVEL
2
3
MAX
UNITS
IV
V
12.2
13.0
12.7
Bits
Bits
IV
V
78
81
80
dB
dB
ADC Input = –1 dBFS2
ADC Input = –0.5 dBFS
IV
V
–92
–82
–84
dB
dB
ADC Input = –1 dBFS
IV
V
75
80
78
dB
dB
85
REXT = 1 kΩ @ 10 MSPS
REXT = 1 kΩ @ 10 MSPS
IV
V
V
V
94
94
83
78
dBc
dBc
dBc
dBc
ƒ1=400 kHz, ƒ2=410 kHz4
ƒ1=890 kHz, ƒ2=900 kHz5
V
V
–94
–89
dB
dB
ADC Input = –0.5 dB
VI
VI
VI
VI
VI
VI
V
IOH = –2 mA
IOL = 2 mA
CLOAD = 20 pF
Power Supply Requirements
Voltages
OVDD
AVDD
DVDD
Currents
IDD
Power Dissipation
1
SPT8100
TYP
ADC Input = –1 dBFS2
Inputs
GS0–GS2 Logic 1 Voltage
GS0–GS2 Logic 0 Voltage
CLK, RS Logic 1 Voltage
CLK, RS Logic 0 Voltage
Maximum Input Current Low
Maximum Input Current High
Input Capacitance
Digital Outputs
Logic 1 Voltage
Logic 0 Voltage
CLK to Output Delay Time (tD)
MIN
Dynamic performance tested at ƒS=4.4 MSPS
0 dBFS is 5.0 V peak-to-peak differential
ADC Input = –8.1 dBFS, unless otherwise noted
TEST LEVEL CODES
All electrical characteristics are subject
to the following conditions:
All parameters having min/max specifications are guaranteed. The Test Level
column indicates the specific device
testing actually performed during
production and Quality Assurance
inspection. Any blank section in the data
column indicates that the specification is
not tested at the specified condition.
4
5
TEST LEVEL
I
II
III
IV
V
VI
2.4
0.8
2.0
0.8
+10
+10
–10
–10
5
VI
VI
IV
OVDD – 0.5
IV
IV
IV
VI
VI
3.0
4.75
4.75
3.3
5.0
5.0
93
465
V
V
V
V
µA
µA
pF
0.4
30
V
V
ns
5.25
5.25
5.25
103
515
V
V
V
mA
mW
Test Conditions: PGA setting of 5.8 dB; Analog Input at ADC = –0.7 dB
Test Conditions: PGA setting of 0 dB; Analog Input at ADC = –1.9 dB
TEST PROCEDURE
100% production tested at the specified temperature.
100% production tested at TA = +25 °C, and sample tested at the
specified temperatures.
QA sample tested only at the specified temperatures.
Parameter is guaranteed (but not tested) by design and characterization data.
Parameter is a typical value for information purposes only.
100% production tested at TA = +25 °C. Parameter is guaranteed
over specified temperature range.
SPT8100
3
1/9/02
DEVICE OVERVIEW
ADC CLOCK
The SPT8100 combines a high-resolution 5 MSPS 16-bit
ADC, a built-in reference, and a programmable gain amplifier (PGA) with resistive input impedance in a 44-pin
package.
The chip requires a single low-jitter clock to be applied at
the CLK pin, with nominal 40–60% duty cycle. All clock
generation is performed internally and all converter and
S/H clocks in the ADC path are directly derived from CLK.
The device includes a digitally calibrated pipeline ADC,
which is calibrated on assertion of a simple reset signal.
The combination of low noise, high linearity, a high-input
impedance buffer (with programmable gain), wideband
S/H, on-board voltage references, and simple digital interface (16-bit parallel output word synchronous with the
master sampling clock) makes the SPT8100 extremely
easy to use in a wide variety of systems.
If the sample rate is changed by more than a factor of 2,
the device must be recalibrated using the RS (reset) pin.
DEVICE STARTUP/INITIALIZATION SEQUENCE
Note: This initialization sequence is required. Without
it, the device will not work.
Allow sufficient time for the analog blocks on the SPT8100
to power on and come up to their quiescent DC states.
Allowance may also be needed for thermal time constants
associated with the package/board.
For optimum performance, the analog inputs should be
driven differentially, and may be AC-coupled or DCcoupled to a source. Typical applications include high-performance data acquisition systems, automatic test equipment, and wideband digital communications receivers
such as wireless basestations.
On powerup, the SPT8100’s RS (reset) should be held low
for at least three clock cycles. The power supply voltages
applied to the device must be stable during this time. The
clock signal (CLK) must be running for at least three clock
cycles prior to the rising edge of RS, and must continue
running.
OPERATIONAL DESCRIPTION
The following sections describe in greater detail individual
blocks and functions of the SPT8100.
When the RS signal goes from low to high, calibration is initiated. RDY is driven low two clock cycles after the rising
edge of RS, and will stay low for 150 ms with a 5 MHz clock.
When the initialization is complete, RDY returns high and
the device is ready for normal operation. Note that the calibration of the ADC can be interrupted (before completion)
by changing the RS signal from high to low, which will
cause another reset to occur. When RS goes from low back
to high, another calibration cycle will begin.
The incoming analog differential signal (maximum level 5 V
peak-to-peak differential) enters the device at the pins
VIN+/VIN–. The analog signal path is partitioned into a programmable gain amplifier (PGA) and an ADC. The PGA
has maximum gain of +19.5 dB; the gain is set by the digital control signals GS0 to GS2.
The output of the PGA is fed directly to the ADC, which
samples at a rate equal to the CLK frequency and outputs
a 16-bit wide parallel word. The ADC uses a pipeline multistage architecture. Latency is 5.5 clock cycles.
RDY cannot be tri-stated: it is always driven either high or
low. The CLK must be constantly running throughout the
Figure 1 – Device Initialization Timing
PWR ON
N+7
N+4
AIN
N+8
N+6
N+5
CLK
RS
3 clock cycles min
5 ns typ
2 clock cycles
RDY
Initialization period: 150 ms with 5 MHz clock
24 ns typ
DOUT
INVALID DATA
N
N+1
N+2
Requires external reset on powerup
SPT8100
4
1/9/02
TYPICAL INTERFACE CIRCUIT
initialization phase until RDY is deasserted. Note that,
although typically the device is initialized when power is
first applied, the initialization is only started when the RS is
asserted; there is no “power-on-reset” circuitry on chip. RS
may be held low for an indefinite period of time. While RS is
low, RDY will remain high. After RS is returned to high, RDY
will go low for the duration of the calibration.
ANALOG INPUT DRIVER
The differential analog inputs (VIN+, VIN–) have a resistive
input impedance of 1 kΩ minimum. For best performance,
the input source should be a differential input, as shown in
figure 2, typical interface circuit. The SPT8100 provides its
own common-mode voltage on the pin marked VCM. Output drive capability of VCM is a maximum of 47 µA (50 kΩ to
ground).
PROGRAMMABLE GAIN AMPLIFIER
The programmable gain amplifier (PGA) precedes the
ADC inputs. The differential inputs, which are resistive, are
at pins VIN+ and VIN–.The maximum input range is 5 V
peak-to-peak differential (2.5 V single-ended). To achieve
maximum overall system noise performance, the source
driving these inputs needs to be as low-noise and as lowjitter as possible, while maintaining the required distortion
performance. In addition, the driving source must be low
impedance to maintain the accuracy of the PGA gain.
The SPT8100 application note (AN8100) shows an example of two modes of driving the SPT8100. One mode is
through a transformer and the other is through a single-todifferential converter. In all cases, both inputs VIN+ and
VIN– must be kept within the input common-mode range
(1.15 V to 3.65 V).
BIASC CONNECTION
The internal 0 dB analog signal level and ADC full-scale
output level is 5 V peak-to-peak differential (2.5 V singleended). The PGA may be used to provide gain for an input
less than 5 V peak-to-peak differential.
An external capacitor, CEXT on the BIASC pin, is used only
for noise filtering of an internal voltage associated with the
references. Its value is not critical: 1 µF in parallel with
0.01 µF is recommended.
The gain of the PGA can be programmed using a three-bit
control, available at pins GS0 to GS2. See table I. Note that
the input resistance is a function of the gain setting.
BIASR CONNECTION
As shown in the typical interface circuit, REXT is needed to
connect between BIASR to ground. This resistor ranges
from 800 Ω to 2.5 kΩ. The proper selection of REXT is a
function of the sample rate and input frequency. Nominally,
at 5 MSPS, REXT=1.43 kΩ is recommended. If linearity for
large signal levels at an analog bandwidth of 2 MHz is critical, the value should be decreased to REXT=1.24 kΩ; and
for even higher-frequency analog inputs, REXT=1.0 kΩ can
be used. At lower sample rates (for example 2 MSPS),
and lower analog input frequencies, the value may be increased to REXT=2 kΩ. (Refer to the typical interface circuit
table in figure 2b.)
Table I – PGA Gain Control
GS2 GS1 GS0
PGA
Input
V/V
Gain Resistance Gain
Ω)
(dB)
(kΩ
3 dB
BW LSBRMS
0
0
0
0
5.57
1
12
1.4
0
0
1
2.9
4.65
1.40
10
1.5
0
1
0
5.8
3.97
1.95
8
1.6
0
1
1
11.8
2.23
3.9
7
2.0
1
0
0
14.8
1.66
5.5
6
2.3
1
0
1
17.5
1.25
7.5
5.5
2.6
1
1
0
19.5
1.00
9.5
5
2.8
1
1
1
X
POWER SUPPLIES AND GROUNDING
The SPT8100 requires three power supplies: analog AVDD,
digital DVDD and output supply OVDD. This device works
best if all three supplies are coming from the analog supply
side of the system as shown in the typical interface circuit
(figure 2a).
Forbidden
Note, in figure 2a, that the supplies to the logic interface
circuit and the OVDD are separate from each other. In a
case where the +A3.3/5 V supply is not available, try to
implement the design as close as possible to that shown
in figure 2b. Place the ferrite bead (FB1) as close to the
device as possible. To avoid latch-up, the delta between
all three grounds must stay with 100 mV; this includes
transients. (Refer to the absolute maximum ratings
specifications.)
SPT8100
5
1/9/02
Figure 2a – Typical Interface Circuit
1.0
+
Gain Control
Reset
Output
Enable Clock
(active Hi) Input
.01
1.43K
BIASC RS GS2 GS1 GS0
BIASR
REXT
CLK
OE
VCM
Transformer
AIN
RDY
VIN+
16
RT
(50)
SPT8100
D0–15
VIN–
Mini-Circuit
T1-6T
0.1
+ 4.7
VRT
+
OVR
VRB
10
0.1
Logic
Interfacing
Circuit
AVDD DVDD AGND DGND OGND
1nF
OVDD
0.1
0.1
10
+
+
10
FB1
+A5V
+A3.3/5V
+D3.3/5V
Figure 2b – Typical Interface Circuit
1.0
+
Gain Control
Reset
Output
Enable Clock
(active Hi) Input
.01
1.43K
BIASC RS GS2 GS1 GS0
BIASR
REXT
OE
CLK
VCM
Transformer
AIN
RDY
VIN+
16
RT
(50)
SPT8100
D0–15
VIN–
Mini-Circuit
T1-6T
0.1
+ 4.7
VRT
+
OVR
VRB
10
0.1
1nF
Logic
Interfacing
Circuit
AVDD DVDD AGND DGND
OGND
OVDD
0.1
0.1
Ω)
ƒS (MSPS) REXT (kΩ
–5
–2
–5
–2
1.43
2.00
1.24
1.00
ƒIN
<2 MHz
<2 MHz
•2 MHz
•2 MHz
10
+
FB2
10
+
+A5V
FB1
FB3
+D3.3/5V
800 Ω – REXT – 2.5 kΩ
Notes:
1. To avoid device latch-up, closely follow either figure 2a or 2b, depending on what is available in the system. The difference between figure 2a
and 2b is in the grounding.
2. FB = ferrite bead. FB1 must be placed as close to the device as possible.
3. REXT = 1.43 kΩ, optimized for ƒS = 5 MSPS. Refer to the above table for recommended value of REXT with respect to ƒS and ƒIN.
4. RT is AIN source termination resistor.
5. Power supplies and references pins must have adequate decoupling. Surface-mount capacitors are highly recommended. The smallest value
of capacitors are to be placed as close to the pin as possible.
SPT8100
6
1/9/02
Figure 3 – Timing Diagram 1
n+1
n
n+2
n+3
n+4
n+5
Analog In
n+6
n+8
n+7
CLK
tD
D0–D15
OVR
n
n+1
n+2
INPUT/OUTPUT TIMING
OUTPUT ENABLE
The SPT8100 implements a simple interface: the 16 ADC
outputs appear on the pins D15–D0 as a parallel word synchronous with the ADC sampling clock. D0 is the LSB and
D15 is the MSB. The timing diagram for the ADC digital
outputs is shown in figure 3. The data is sampled at the falling edge of the clock. The ADC sampling clock is at the
same frequency as CLK.
The ADC digital outputs are enabled by the active high
output enable pin (OE).
OE = 1: ADC digital outputs are enabled
OE = 0: ADC digital outputs are high-impedance
(tri-stated)
DIGITAL CODE RANGE AND
OUT-OF-RANGE DETECTION
The output data is updated on the rising edge of CLK with
a clock latency of 5.5 clock cycles.
The output format of the ADC digital data is offset binary.
Due to the calibration algorithm used, there is a slight loss
in digital code range from the ADC. Instead of FFFFH and
0000H at the extremes of the range, the actual maximum
and minimum codes are less than that by 1.6% at both
ends of the scale, and vary from chip to chip. Effectively,
this is a loss in dynamic range of a few tenths of a dB, and
is negligible in many applications. The out-of-range function is defined accordingly, and sets the state of the active
high digital output OVR, as follows:
OUTPUT LOGIC LEVEL
The voltage levels on the D15–D0 lines and OVR are
CMOS levels: the HIGH level is determined by the power
supply voltage on the OVDD pin, which can be set independently of the other supply pins on the device over the range
from 3.0 V to 5.25 V (3.3 V typical). The RDY pin level is
determined by DVDD (+5 V).The external digital output
buffers should be placed as close as possible to the
SPT8100 digital outputs to minimize any line reflections
that would cause performance degradation.
OVR is HIGH if the ADC digital code is greater
than or equal to FC00H or less than or equal to
03FFH. (See figure 4.)
ADC REFERENCES
If the output code exceeds FC00(max) or 03FF(min), this
implies that output is clipping. Therefore, once these limits
are crossed, the second harmonic becomes significant
and degrades performance.
The ADC full-scale range is set by reference voltages generated on chip. These two reference voltages appear on
pins VRT and VRB; nominally their difference is 2.5 V. The
references are not designed to be overdriven. The VRT and
VRB pins should be very carefully decoupled on the board
using as short a trace as possible. Some optimization of
the decoupling may be required, as shown in the typical
interface circuit diagram. The smallest capacitor should be
the closest one to the chip. (Refer to the typical interface
circuit diagram.)
Figure 4 – ADC Digital Code Range and Overrange
Bit Function
FFFFH
65535
OVR = 1
ADC
Digital Code
Range
OVR = Ø
03FFH
1023
OVR = 1
0000H
1.6% FSR
64512
FC00H
1.6% FSR
0
SPT8100
7
1/9/02
Table II – Timing Parameters
Figure 5 – Timing Diagram 2
CLK
Parameter
tD1
Digital
Outputs
tD2
Min Typ Max
Units
CLK high to Data Valid
tD1
18
24
401
OE inactive to HiZ
tD2
10
16
30
ns
OE active to Data Valid
tD3
10
16
30
ns
1
OE
Symbol
ns
Conditions: load capacitance = 20 pF, VOH = 3.3 V
tD3
Typical Differential Linearity Error (DLE)
DLE (LSB)
FFT Plot
Test Conditions:
ƒIN = 2 MHz
ƒCLK = 4.4 MHz
PGA Gain = 18 dB
Test Conditions:
ƒIN = 75 kHz
ƒCLK = 4.4 MHz
REXT = 1.08 kΩ
ADC Input (Post PGA) = –5.4 dBFS
TA = +25 °C
Two-Tone Intermodulation FFT
PGA Gain = 0 dB
Near Full-Scale Input
Spurious-Free Dynamic Range
100
0.9 MHz, low
95
90
0.9 MHz, med
0.9 MHz, high
85
SFDR (dBc)
80
2 MHz, high
75
2 MHz, med
70
2 MHz, low
65
3 MHz, high
60
55
3 MHz, med
50
Test Conditions:
ƒ1 = 890 kHz
ƒ2 = 900 kHz
ƒCLK = 4.4 MHz
PGA Gain = 6 dB
3 MHz, low
REXT = 1.43 kΩ
ADC Input (Post PGA) = –8.0 dBFS
TA = +25 °C
45
–10
–9
–8
–7
–6
–5
–4
–3
–2
–1
Composite Level at ADC Input (dBFS)
0
5 VP-P
Test Conditions:
Med: REXT=1.24 kΩ @109 mA
10 MSPS, 5 V, 25 °C
Low: REXT=1.43 kΩ @96 mA High: REXT=1 kΩ @129 mA
SPT8100
8
1/9/02
PACKAGE OUTLINE
44-Lead LQFP
A
B
SYMBOL
Pin 1
Index
0.465
0.480
11.80
12.20
B
0.390
0.398
9.90
10.10
C
0.390
0.398
9.90
10.10
D
0.465
0.480
11.80
12.20
F
E
D
MILLIMETERS
MIN
MAX
A
E
C
INCHES
MIN
MAX
0.0315 BSC
0.012
0.018
0.80 BSC
0.30
0.45
G
0.053
0.057
1.35
1.45
H
0.002
0.006
0.05
0.15
I
0.018
0.030
0.45
0.75
J
0.039 typ
1.0 typ
K
0–7°
0–7°
F
G
H
K
I
J
SPT8100
9
1/9/02
PIN ASSIGNMENTS
PIN FUNCTIONS
BIASC
BIASR
VRB
VRT
AGND
VCM
GS1
VIN+
GS0
VIN–
AVDD
Pin Name Description
34
35
36
37
39
38
40
41
43
42
44
AGND
Analog ground
DGND
Digital ground
D0–D15
Data output bits; D0 is LSB; D15 is MSB
CLK
7
27
GS2
OVR
Overrange indicator bit (active high)
OE
8
26
N/C
N/C
No connect
D0 (LSB)
9
25
OVR
GS[2:0]
3-bit PGA gain setting control inputs
10
24
D15 (MSB)
AVDD
Analog +5.0 V supply
11
23
D14
RS
Resets internal state of chip (active low)
RDY
Initialization in progress indicator; RDY goes low
during reset initialization. Chip is ready for normal
operation when RDY is high.
BIASC
External bias capacitor connection
BIASR
External bias resistor connection
VRT, VRB
ADC reference voltage outputs
VCM
Common mode reference voltage output
D1
D2
D13
AVDD
D12
28
22
Output enable (active high)
6
D11
OE
OVDD
21
AGND
D10
29
20
5
19
OGND
D9
Master reference clock
D8
CLK
18
RS
17
Digital outputs supply (+3.3/5 V)
30
D7
OVDD
4
D6
N/C
DVDD
16
3
31
15
Ground for digital I/O
DVDD
D5
Digital +5.0 V supply
OGND
D4
DVDD
N/C
14
RDY
32
13
33
2
D3
1
12
AGND
DGND
VIN+, VIN– Analog inputs to the PGA
ORDERING INFORMATION
PART NUMBER
SPT8100SIT
TEMPERATURE RANGE
PACKAGE
–40 to +85 °C
44L LQFP
DISCLAIMER
FAIRCHILD SEMICONDUCTOR RESERVES THE RIGHT TO MAKE CHANGES WITHOUT FURTHER NOTICE TO ANY PRODUCTS HEREIN TO
IMPROVE RELIABILITY, FUNCTION OR DESIGN. FAIRCHILD DOES NOT ASSUME ANY LIABILITY ARISING OUT OF THE APPLICATION OR
USE OF ANY PRODUCT OR CIRCUIT DESCRIBED HEREIN; NEITHER DOES IT CONVEY ANY LICENSE UNDER ITS PATENT RIGHTS, NOR
THE RIGHTS OF OTHERS.
LIFE SUPPORT POLICY
FAIRCHILD'S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS
WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT OF FAIRCHILD SEMICONDUCTOR CORPORATION. As used herein:
1. Life support devices or systems are devices or systems which, (a) are
intended for surgical implant into the body, or (b) support or sustain life,
and whose failure to perform, when properly used in accordance with
instructions for use provided in the labeling, can be reasonably
expected to result in a significant injury to the user.
2. A critical component is any component of a life support device or
system whose failure to perform can be reasonably expected to cause
the failure of the life support device or system, or to affect its safety or
effectiveness.
www.fairchildsemi.com
© Copyright 2002 Fairchild Semiconductor Corporation
SPT8100
10
1/9/02