•RAD-PAK® radiation-hardened against natural space radia-
tion
• Total dose hardness:
- > 100 krad (Si), depending upon space mission
• Latch-up Protection Technology (LPT
• SEL converted into a reset
- Rate based on cross section and mission
• Same footprint as ADS7809
• Package: 24 pin R
AD-PAK flat package
• 100 kHz min sampling rate
• ±10 V and 0 V to 5 V input range
• Advanced CMOS technology
• DNL: 15-bits “No Missing Codes”
• 83 dB min SINAD with 20 kHz input
• Single +5 V supply operation
• Utilizes internal or external reference
• Serial output
• Power dissipation: 132 mW max
TM
)
Buffer
Successive Approximation Register and Control Logic
CDAC
Comparator
Internal
4 k
Ω
+2.5V Ref.
Clock
Serial Data
Out
Logic Diagram
DESCRIPTION:
Maxwell Technologies’ 7809LP high-speed 16-bit analog to
digital converter features a greater than 100 kilorad (Si) total
dose tolerance depending upon space mission. Using Maxwell’s radiation-hardened R
7809LP has the same footprint as ADS7809 and is latchup
protected by Maxwell Technologies’ Latchup Protection Technology (LPT
TM
). It is a 24 pin, 16-bit sampling analog-to-digital
converter using state-of-the-art CMOS structures. The
7809LP contains a 16-bit capacitor based SAR A/D with S/H,
reference, clock, interface for microprocessor use, and serial
output drivers. The 7809LP is specified at a 100kHz sampling
rate, and guaranteed over the full temperature range. Lasertrimmed scaling resistors provide various input ranges include
±10 V and 0 to 5 V, while the innovative design allows operation from a single +5 V supply, with power dissipation of under
132 mW.
Maxwell Technologies' patented R
ogy incorporates radiation shielding in the microcircuit package. It eliminates the need for box shielding while providing
the required radiation shielding for a lifetime in orbit or space
mission. In a GEO orbit, R
krad (Si) radiation dose tolerance. This product is available
with screening up to Class K.
16-Bit Latchup Protected Analog to Digital Converter
TABLE 1. 7809LP PIN DESCRIPTION
PINSYMBOLDESCRIPTION
1R1INAnalog Input.
2AGND1Analog Ground. Used internally as ground reference point.
3R2INAnalog Input.
4R3INAnalog Input.
5CAPReference Buffer Capacitor. 2.2 µF tantalum to ground.
6REFReference Input/Output. 2.2 µF tantalum capacitor to ground.
7AGND2Analog Ground.
8SB/BTC
9EXT/INTSelect External or Internal Clock for transmitting data. If HIGH, data will be output synchronized
Select Straight Binary or Binary Two’s Complement data output format. If HIGH, data will be
output in a Straight Binary format. If LOW, data will be output in a Binary Two’s Complement
format.
to the clock input on DATACLK. If LOW, a convert command will initiate the transmission of the
data from the previous conversion, along with 16 clock pulses output on DATACLK.
7809LP
Memory
10DGNDDigital Ground.
11LPBITBuilt In test function of the latchup protection. Drive LOW during normal operation.
12LPSTATUS Latchup Protection Status Output. LPSTATUS when HIGH indicates latchup protection is
active and output data is invalid.
13VANAAnalog Supply Input. Nominally 5V.
14VDIGDigital Supply Input. Nominally 5V.
15SYNCSync Output. If EXT/INT is HIGH, either a rising edge on R/C
CS
with R/C HIGH will output a pulse on SYNC synchronized to the external DATACLK.
16DATACLKEither an input or an output depending on the EXT/INT level. Output data will be synchronized
to this clock. If EXT/INT is LOW, DATACLK will transmit 16 pulses after each conversion, and
then remain LOW between conversions.
17DATASerial Data Output. Data will be synchronized to DATACLK, with the format determined by the
level of SB/BTC
level input of TAG as long as CS
on both the rising and falling edges of DATACLK, and between conversions DATA will stay at
the level of the TAG input when the conversion was started.
18TAGTag input for use in external clock mode. If EXT/INT is HIGH, the digital data input on TAG will
be output on DATA with a delay of 16 DATACLK pulses as long as C
HIGH.
19R/C
20CS
Read/Convert Input. With CS LOW, a falling edge on R/C puts the internal sample/hold into the
hold state and starts a conversion. When EXT/INT is LOW, this also initiates the transmission
of the data results from the previous conversion. If EXT/INT is HIGH, a rising edge on R/C
C
S LOW, or a falling edge on CS with R/C HIGH, transmits a pulse on SYNC and initiates the
transmission of data from the previous conversion.
Chip Select. Internally OR’ed with R/C.
. In the external clock mode, after 16-bits of data, the 7809LOPO will output the
is LOW and R/C is HIGH. If EXT/INT is LOW, data will be valid
with CS LOW or a falling edge on
S is LOW and R/C is
with
1000585
12.19.01 Rev 3
All data sheets are subject to change without notice
16-Bit Latchup Protected Analog to Digital Converter
7809LP
TABLE 3. 7809LP DC ACCURACY SPECIFICATIONS
(SPECIFIED PERFORMANCE -40 TO +85°C)
P
ARAMETERMINTYPMAXUNIT
Full Scale Error Drift (using ext. 2.5000 V
Bipolar Zero Error
4
Bipolar Zero Error Drift--±2--ppm/
Unipolar Zero Error
4
-40 to 85°C
Unipolar Zero Error Drift--±2--ppm/
Recovery to Rated Accuracy after Power Down (1 uF Capacitor to
)--±2--ppm/°C
ref
----±10mV
--
--
--
--
±3
±16
--1--ms
mV
mV
°
C
°
C
CAP)
Power Supply Sensitivity (V
-40 to 85°C
DIG
= V
= VD) 4.75 V > VD < 5.2 V
ANA
--
--
--
--
±8
±32
LSB
LSB
1. LSB stands for Least Significant Bit. One LSB is equal to 305 µV.
2. Not tested.
3. Typical rms noise at worst case transitions and temperatures.
4. Measured with various fixed resistors.
5. For bipolar input ranges, full scale error is the worst case of -Full Scale or +Full Scale untrimmed deviation from ideal first and
last scale code transitions, divided by the transition voltage (not divided by the full-scale range) and includes the effect of offset
error. For unipolar input ranges, full scale error is the deviation of the last code transition divided by the transition voltage. It
also includes the effect of offset error.
Memory
TABLE 4. 7809LP DIGITAL INPUTS
(SPECIFIED PERFORMANCE -40 TO +85°C)
P
ARAMETERMINTYPMAXUNIT
V
IL
V
IH
IIL, I
IH
-0.3
2.0
--
--
--
--
V
0.8
+ 0.3
D
±10
TABLE 5. 7809LP ANALOG INPUTAND THROUGHPUT SPEED
(SPECIFIED PERFORMANCE -40 TO +85°C)
P
ARAMETERMINTYPMAXUNIT
Voltage Ranges10 V, 0 V to 5 V
Impedance
Capacitance--35--pF
Conversion Time--7.68µs
Complete Cycle (Acquire and Convert)----10µs
Throughput Rate
1
100----kHz
1. Tested by application of signal.
See Table 2.
V
V
µA
1000585
12.19.01 Rev 3
All data sheets are subject to change without notice