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 theADC101C021 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)
|