ADC121S101/ADC101S101/ADC081S101
1MSPS, 12-/10-/8-Bit A/D Converters in SOT-23 & LLP
General Description
The ADC121S101, ADC101S101, and ADC081S101 are low
power, monolithic CMOS 12-, 10- and 8-bit analog-to-digital
converters that operate at 1 MSPS. Each device is based on
a successive approximation register architecture with inter-
nal track-and-hold. The serial interface is compatible with
several standards, such as SPI™, QSPI™, MICROWIRE™,
and many common DSP serial interfaces.
The ADC121S101/101S101/081S101 uses the supply volt-
age as a reference. This enables the devices to operate with
a full-scale input range of 0 to V
DD
. The conversion rate is
determined from the serial clock (SCLK) speed. These con-
verters offer a shutdown mode, which can be used to trade
throughput for power consumption. The ADC121S101/
101S101/081S101 are operated with a single supply that
can range from +2.7V to +5.25V. Normal power consumption
during continuous conversion, using a +3V or +5V supply, is
2 mW or 10 mW, respectively. The power down feature,
which is enabled by a chip select (CS) pin, reduces the
power consumption to under 5 µW using a +5V supply. All
three converters are available in a 6-lead SOT-23 package,
which provides an extremely small footprint for applications
where space is a critical consideration. The ADC081S101 is
also available in a 6-lead LLP package. These products are
designed for operation over the industrial temperature range
of −40˚C to +85˚C, with some parameters specified to
+125˚C for the ADC121S101.
Features
n Variable power management
n Packaged in 6-lead SOT-23 (ADC081S101 also
available in a 6-Lead LLP package)
n Power supply used as reference
n Single +2.7V to +5.25V supply operation
n SPI™/QSPI™/MICROWIRE™/DSP compatible
Key Specifications
n Resolution with no Missing Codes 12/10/8 bits
n Conversion Rate 1 MSPS
n DNL (ADC121S101) +0.5, -0.3 LSB (typ)
n INL (ADC121S101) ± 0.4 LSB (typ)
n Power Consumption
— 3V Supply 2 mW (typ)
— 5V Supply 10 mW (typ)
Applications
n Automotive Navigation
n FA/ATM Equipment
n Portable Systems
n Medical Instruments
n Mobile Communications
n Instrumentation and Control Systems
Connection Diagram
20110201
MICROWIRE™ is a trademark of National Semiconductor Corporation.
TRI-STATE
®
is a trademark of National Semiconductor Corporation.
QSPI™ and SPI™ are trademarks of Motorola, Inc.
January 2005
ADC121S101/ADC101S101/ADC081S101
1MSPS,
12-/10-/8-Bit
A/D
Converters
in
SOT
-23
&
LLP
© 2005 National Semiconductor Corporation DS201102 www.national.com