Overview
The AD22105AR, produced by Analog Devices Inc., is a solid-state thermostatic switch designed for precise temperature control. This device requires only one external programming resistor to set the temperature switchpoint accurately within a wide operating range of -40°C to +150°C. It utilizes a novel circuit architecture that combines the functions of a temperature sensor, setpoint comparator, and output stage in a single integrated circuit. The AD22105AR operates on a single power supply voltage from 2.7 V to 7.0 V, making it suitable for both battery-powered applications and industrial control systems. Its low power dissipation of 230 µW at 3.3 V minimizes self-heating errors and maximizes battery life.
Key Specifications
| Parameter | Symbol | Min | Typ | Max | Unit |
|---|---|---|---|---|---|
| Temperature Accuracy | ACC | ±0.5 | ±2.0 | °C | |
| Temperature Setpoint Accuracy | ACCT | - | ±3.0 | °C | |
| Power Supply Rejection | PSR | ±0.05 | ±0.15 | °C/V | |
| Hysteresis | HYS | - | 4.1 | °C | |
| Output Low Voltage | VOL | 250 | 400 | mV | |
| Supply Voltage Range | VS | 2.7 | - | 7.0 | V |
| Supply Current (Output Low) | ISON | - | 120 | µA | |
| Supply Current (Output High) | ISOFF | - | 90 | µA | |
| Internal Pull-Up Resistor | RPULL-UP | 140 | 200 | 260 | kΩ |
| Turn-On Settling Time | tON | - | 5 | µs |
Key Features
- User-programmable temperature setpoint using a single external resistor.
- Wide operating temperature range: -40°C to +150°C.
- Low power dissipation: 230 µW at 3.3 V.
- Single power supply voltage range: 2.7 V to 7.0 V.
- Approximately 4°C of hysteresis to prevent rapid thermal on/off cycling.
- Optional internal 200 kΩ pull-up resistor for driving light loads such as CMOS inputs or low power LED indicators.
- Open collector output.
Applications
- Industrial process control and thermal control systems.
- CPU monitoring and computer thermal management circuits.
- Fan control systems.
- Handheld and portable electronic equipment.
- Battery-powered applications.
Q & A
- What is the operating temperature range of the AD22105AR?
The AD22105AR operates within a temperature range of -40°C to +150°C.
- How is the temperature setpoint programmed on the AD22105AR?
The temperature setpoint is programmed using a single external resistor connected between the RSET pin and the GND pin.
- What is the power supply voltage range for the AD22105AR?
The AD22105AR operates on a single power supply voltage from 2.7 V to 7.0 V.
- What is the typical power dissipation of the AD22105AR?
The typical power dissipation is 230 µW at 3.3 V.
- What is the hysteresis value of the AD22105AR?
The AD22105AR has approximately 4°C of hysteresis.
- What type of output does the AD22105AR have?
The AD22105AR has an open collector output.
- Can the AD22105AR drive light loads directly?
Yes, the AD22105AR can drive light loads such as CMOS inputs or low power LED indicators using an optional internal 200 kΩ pull-up resistor.
- What is the turn-on settling time of the AD22105AR?
The turn-on settling time is approximately 5 µs.
- What are some common applications of the AD22105AR?
Common applications include industrial process control, CPU monitoring, fan control, and handheld/portable electronic equipment.
- What is the package type of the AD22105AR?
The AD22105AR is available in an 8-Lead SOIC (SO-8) package.
