Overview
The LMC7221BIM5X/NOPB is a micropower CMOS comparator produced by Texas Instruments. It is available in a space-saving 5-Pin SOT-23 package, making it ideal for designs where space and weight are critical. This comparator features rail-to-rail input and an open drain output, which is particularly useful in mixed voltage systems and for direct sensor interfacing. The LMC7221 operates at supply voltages as low as 2.7V, making it suitable for low voltage applications and 3V digital systems.
Key Specifications
| Parameter | Test Conditions | Typical Value | Limit Value | Units |
|---|---|---|---|---|
| Input Offset Voltage (VOS) | V+ = 2.7V, 5V, 15V | 3 mV, 5 mV, 15 mV | 8 mV, 18 mV | mV |
| Input Current (IB) | TJ = 25°C | 0.04 pA | - | pA |
| Input Offset Current (IOS) | TJ = 25°C | 0.02 pA | - | pA |
| Common Mode Rejection Ratio (CMRR) | V+ = 5.0V, 15.0V | 75 dB, 82 dB | - | dB |
| Supply Current (IS) | VOUT = Low | 7 μA, 14 μA | 18 μA | μA |
| Response Time | V+ = 5V, Overdrive = 100 mV | 4 μs | - | μs |
| Output Voltage Low (VOL) | ILOAD = 5 mA | 0.2 V, 0.4 V | 0.55 V | V |
| Input Common-Mode Voltage Range (CMVR) | V+ = 5.0V, 15.0V | -0.3 V to V+, -0.3 V to V+ | - | V |
Key Features
- Tiny Package: Available in a 5-Pin SOT-23 package, which is less than 1.43 mm thick, making it ideal for space and weight critical designs.
- Rail-to-Rail Input: The input common-mode voltage range extends beyond the supply rails, allowing the comparator to sense signals near the positive rail and below the negative rail.
- Open Drain Output: The open drain output can be pulled up with a resistor to a voltage higher or lower than the supply voltage, making it useful in mixed voltage systems.
- Low Power Consumption: Typical supply current of 7 μA at 5V, making it suitable for battery-powered applications.
- Fast Response Time: Response time of 4 μs at 5V with an overdrive of 100 mV.
- Direct Sensor Interfacing: Can directly interface with sensors without the need for amplifiers or bias circuits, saving cost, space, and design time.
- Low Voltage Operation: Operates at supply voltages as low as 2.7V, making it suitable for low voltage applications and 3V digital systems.
Applications
- Mixed Voltage Battery Powered Products: Ideal for devices that operate on multiple voltage levels.
- Notebooks and PDAs: Suitable for portable electronic devices due to its low power consumption and small package size.
- PCMCIA Cards: Used in PCMCIA cards for their compact size and low power requirements.
- Mobile Communications: Used in mobile communication devices for its low power and compact design.
- Alarm and Security Circuits: Can be used in alarm and security systems due to its fast response time and low power consumption.
- Driving Low Current LEDs: Can be used to drive low current LEDs directly.
Q & A
- What is the typical supply current of the LMC7221 at 5V?
The typical supply current is 7 μA at 5V.
- What is the response time of the LMC7221 at 5V with an overdrive of 100 mV?
The response time is 4 μs at 5V with an overdrive of 100 mV.
- What are the available package types for the LMC7221?
The LMC7221 is available in 5-Pin SOT-23 and 8-Pin SOIC packages.
- What is the input common-mode voltage range for the LMC7221?
The input common-mode voltage range extends beyond the supply rails, from -0.3V to V+ for both 5V and 15V supplies.
- Can the LMC7221 be used for direct sensor interfacing?
Yes, the LMC7221 can directly interface with sensors without the need for amplifiers or bias circuits.
- What is the maximum operating temperature range for the LMC7221?
The operating temperature range is from -40°C to 85°C.
- What is the typical input offset voltage for the LMC7221?
The typical input offset voltage is 3 mV, 5 mV, and 15 mV for different grades.
- How does the open drain output of the LMC7221 work?
The open drain output can be pulled up with a resistor to a voltage higher or lower than the supply voltage, making it useful in mixed voltage systems.
- Is the LMC7221 suitable for low voltage applications?
Yes, the LMC7221 operates at supply voltages as low as 2.7V, making it suitable for low voltage applications and 3V digital systems.
- What are some common applications of the LMC7221?
Common applications include mixed voltage battery powered products, notebooks, PDAs, PCMCIA cards, mobile communications, alarm and security circuits, and driving low current LEDs).
