Features
| • | I
2C-Compatible 2-wire Interface which supports standard (100kHz), fast (400kHz), and high speed (3.4MHz) modes
|
| • | Extended power supply range (+2.7V to +5.5V) |
| • | Up to nine pin-selectable chip addresses (MSOP-8 only) |
| • | Out-of-range Alert Function |
| • | Automatic Power-down mode while not converting |
| • | Very small TSOT-6 and MSOP-8 packages |
| • | ±8kV HBM ESD protection (SDA, SCL) |
Description These converters are low-power, monolithic, 12-bit, analog-to-digital converters (ADCs) that operates from a +2.7 to 5.5V
supply. The converter is based upon a successive approximation register architecture with an internal track-and-hold circuit
that can handle input frequencies up to 11MHz. These converters operate from a single supply which also serves as the reference.
The device features an
I
2C-compatible
serial interface that operates in all three speed modes, including high speed mode (3.4MHz).
The ADC121C021's Alert feature provides an interrupt that is activated when the analog input violates a programmable upper
or lower limit value. The device features an automatic conversion mode, which frees up the controller and I
2C interface. In this mode, the ADC continuously monitors the analog input for an "out-of-range" condition and provides
an interrupt if the measured voltage goes out-of-range.
The ADC121C021 comes in two packages: a small TSOT-6 package with an alert output, and an MSOP-8 package with an alert output
and two address selection inputs. The
ADC121C027 comes in a small TSOT-6 package with an address selection input. The
ADC121C027 provides three pin-selectable addresses while the MSOP-8 version of the ADC121C021 provides nine pin-selectable addresses.
Pin-compatible alternatives to the TSOT-6 options are available with additional address options.
Normal power consumption using a +3V or +5V supply is 0.26mW or 0.78mW, respectively. The automatic power-down feature
reduces the power consumption to less than 1µW while not converting. Operation over the industrial temperature range of −40°C
to +105°C is guaranteed. Their low power consumption and small packages make this family of ADCs an excellent choice for use
in battery operated equipment.
The
ADC121C021 and
ADC121C027 are part of a family of pin-compatible ADCs that also provide 8 and 10 bit resolution. For 8-bit ADCs see the
ADC081C021 and
ADC081C027. For 10-bit ADCs see the
ADC101C021 and
ADC101C027.
Key Specification
|
Resolution
|
12 bits; no missing codes
|
|
Conversion Time
|
1µs (typ)
|
|
INL & DNL
|
±1 LSB (max) (up to 22ksps)
|
|
Throughput Rate
|
188.9ksps (max)
|
|
Power Consumption (at 22ksps)
|
|
3V Supply
|
0.26 mW (typ)
|
|
5V Supply
|
0.78 mW (typ)
|
Applications
| • | System Monitoring |
| • | Peak Detection |
| • | Portable Instruments |
| • | Medical Instruments |
| • | Test Equipment |
| 
ADC121C021
