Micrel, Inc. MIC7211/7221 MIC7211/7221 IttyBitty® Rail-to-Rail Input Comparator General Description Features The MIC7211 and MIC7221 are micropower comparators featuring rail-to-rail input performance in Micrel’s IttyBitty® SOT-23-5 package. The MIC7211/21 is ideal for systems where small size is a critical consideration. • • • • • • • • The MIC7211/21 is optimized for single supply operation from 2.2V to 10V power supplies. The MIC7211 features a conventional push-pull output while the MIC7221 has an open-drain output for mixed-voltage applications with an external pull-up resistor. Small footprint SOT-23-5 package Guaranteed performance at 2.2V, 2.7V, 5V, and 10V 7µA typical supply current at 5V <5µs response time at 5V Push-pull output (MIC7211) Open-drain output (MIC7221) Input voltage range may exceed supply voltage by 0.3V >100mA typical sink or source Applications The MIC7211/21 benefits small battery-operated portable electronic devices where small size and the ability to place the comparator close to the signal source are primary design concerns. • • • • • • Battery-powered products Notebook computers and PDAs PCMCIA cards Cellular and other wireless communication devices Alarm and security circuits Direct sensor interface Ordering Information Part Number Marking Temp. Range Package Lead Finish MIC7211BM5 A14 –40°C to +85°C SOT-23-5 Standard MIC7221BM5 A15 –40°C to +85°C SOT-23-5 Standard MIC7211YM5 A14 –40°C to +85°C SOT-23-5 Pb-Free MIC7221YM5 A15 –40°C to +85°C SOT-23-5 Pb-Free Pin Configuration IN+ 3 V+ OUT 2 1 Axx Functional Configuration IN+ Part Identification 3 V+ OUT 2 1 4 5 4 5 IN– V– IN– V– SOT-23-5 (M5) Pin Description Pin Number Pin Name 1 OUT Pin Function Amplifier Output 2 V+ Positive Supply 3 IN+ Noninverting Input 4 IN– Inverting Input 5 V– Negative Suppy Micrel, Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 (408) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com October 2009 1 M9999-100909 Micrel, Inc. MIC7211/7221 Absolute Maximum Ratings (Note 1) Operating Ratings (Note 2) Supply Voltage (VV+ – VV–)............................................ 12V Differential Input Voltage (VIN+, VIN–)............... ±(VV+ – VV–) I/O Pin Voltage (VIN+, VOUT), Note 3 . ................................. . .............................................VV+ + 0.3V to VV– – 0.3V Junction Temperature (TJ)........................................ +150°C Storage Temperature (TS)......................... –65°C to +150°C ESD, Note 6 Supply Voltage (VV+ – VV–)................................2.2V to 10V Junction Temperature (TJ)........................... –40°C to +85°C Package Thermal Resistance (θJA) Note 5 . ............ 235°C/W Maximum Power Dissipation..................................... Note 4 DC Electrical Characteristics (2.2V) VV+ = +2.2V, VV– = 0V, VCM = VOUT = VV+/2; TJ = 25°C, bold values indicate –40°C ≤ TJ ≤ +85°C; Note 7; unless noted Symbol VOS Parameter Condition Min Input Offset Voltage Typ Max 2 10 Units mV TCVOS Input Offset Voltage 1 Temperature Drift µV/°C TCVOS Input Offset Voltage 3.3 Drift Over Time µV⁄month IB Input Bias Current 0.5 pA IOS Input Offset Current 0.25 pA CMRR Common-Mode Rejection Ratio dB Positive Power Supply Rejection Ratio 0V ≤ VCM ≤ 2.2V 60 PSRR 90 dB AVOL VV+ = 2.2V to 5V Gain 125 dB VOH Output Voltage (High) 2.18 V IS Supply Current VOL Output Voltage (Low) MIC7211, ILOAD = 2.5mA 2.1 ILOAD = 2.5mA VOUT = low 0.02 0.1 V 5 12 µA Typ Max Units 2 10 DC Electrical Characteristics (2.7V) VV+ = +2.7V, VV– = 0V, VCM = VOUT = VV+/2; TJ = 25°C, bold values indicate –40°C ≤ TJ ≤ +85°C; Note 7; unless noted Symbol VOS Parameter Condition Min Input Offset Voltage mV TCVOS Input Offset Voltage 1 Temperature Drift µV/°C TCVOS Input Offset Voltage 3.3 Drift Over Time µV⁄month IB Input Bias Current 0.5 pA IOS Input Offset Current 0.25 pA CMRR Common-Mode Rejection Ratio dB Positive Power Supply Rejection Ratio 0V ≤ VCM ≤ 2.7V 65 PSRR 90 dB AVOL VV+ = 2.7V to 5V Gain 125 dB VOH Output Voltage (High) 2.68 V IS Supply Current VOL Output Voltage (Low) October 2009 MIC7211, ILOAD = 2.5mA 2.6 ILOAD = 2.5mA VOUT = low 2 0.02 0.1 V 5 12 µA M9999-100909 Micrel, Inc. MIC7211/7221 DC Electrical Characteristics (5V) VV+ = +5.0V, VV– = 0V, VCM = VOUT = VV+/2; TJ = 25°C, bold values indicate –40°C ≤ TJ ≤ +85°C; Note 7; unless noted Symbol Parameter VOS Input Offset Voltage Condition Min Typ Max Units 2 10 mV TCVOS Input Offset Voltage 1 Temperature Drift µV/°C TCVOS Input Offset Voltage 3.3 Drift Over Time µV⁄month IB Input Bias Current 0.5 pA IOS Input Offset Current 0.25 pA CMRR Common-Mode Rejection Ratio 70 dB PSRR Positive Power Supply Rejection Ratio 0V ≤ VCM ≤ 5.0V VV+ = 5.0V to 10V 90 dB AVOL Gain 125 dB VOL Output Voltage (Low) VOH Output Voltage (High) IS Supply Current ISC Short Circuit Current MIC7211, ILOAD = 5mA 4.95 V ILOAD = 5mA 4.9 0.05 0.1 V 7 14 MIC7211, sourcing 150 mA sinking 110 mA VOUT = low µA DC Electrical Characteristics (10V) VV+ = +10V, VV– = 0V, VCM = VOUT = VV+/2; TJ = 25°C, bold values indicate –40°C ≤ TJ ≤ +85°C; Note 7; unless noted Symbol Parameter Condition Min Typ Max 2 10 Units VOS Input Offset Voltage TCVOS Input Offset Voltage 1 Temperature Drift µV/°C TCVOS Input Offset Voltage 3.3 Drift Over Time µV⁄month IB mV Input Bias Current 0.5 pA IOS Input Offset Current 0.25 pA CMRR Common-Mode Rejection Ratio dB Positive Power Supply Rejection Ratio 0V ≤ VCM ≤ 10V 75 PSRR 90 dB AVOL VV+ = 5.0V to 10V Gain 125 dB VOH Output Voltage (High) 9.95 V IS Supply Current VOL ISC Output Voltage (Low) Short Circuit Current October 2009 MIC7211, ILOAD = 5mA 9.9 ILOAD = 5mA VOUT = low 0.05 0.1 V 12 25 µA MIC7211, sourcing 165 mA sinking 125 mA 3 M9999-100909 Micrel, Inc. MIC7211/7221 AC Electrical Characteristics VV– = 0V, VCM = VOUT = VV+/2; TJ = 25°C, bold values indicate –40°C ≤ TJ ≤ +85°C; Note 7; unless noted Symbol Parameter Condition Min Typ Max Units Rise Time tRISE VV+ = 5.0V, f = 10kHz, CLOAD = 50pF overdrive = 10mV, Note 9 75 ns Fall Time tFALL VV+ = 5.0V, f = 10kHz, CLOAD = 50pF overdrive = 10mV, Note 9 70 ns Propagation Delay-High to Low tPHL VV+ = 2.2V, f = 10kHz, CLOAD = 50pF overdrive = 10mV, Note 9 10 µs VV+ = 2.2V, f = 10kHz, CLOAD = 50pF overdrive = 100mV, Note 9 6.0 µs VV+ = 5.0V, f = 10kHz, CLOAD = 50pF overdrive = 10mV, Note 9 13 µs VV+ = 5.0V, f = 10kHz, CLOAD = 50pF overdrive = 100mV, Note 9 5 µs Propagation Delay-Low to High tPLH VV+ = 2.2V, f = 10kHz, CLOAD = 50pF overdrive = 10mV, Note 9 13.5 µs VV+ = 2.2V, f = 10kHz, CLOAD = 50pF overdrive = 100mV, Note 9 4.0 µs VV+ = 5.0V, f = 10kHz, CLOAD = 50pF overdrive = 10mV, Note 9 11.5 µs VV+ = 5.0V, f = 10kHz, CLOAD = 50pF overdrive = 100mV, Note 9 3.0 µs Note 1. Exceeding the absolute maximum rating may damage the device. Note 2. The device is not guaranteed to function outside its operating rating. Note 3. I/O pin voltage is any external voltage to which an input or output is referenced. Note 4. The maximum allowable power dissipation is a function of the maximum junction temperature, TJ(max); the junction-to-ambient thermal resistance, θJA; and the ambient temperature, TA. The maximum allowable power dissipation at any ambient temperature is calculated using PD(max) = (TJ(max) – TA) ÷ θJA. Exceeding the maximum allowable power dissipation will result in excessive die temperature. Note 5. Thermal resistance, θJA, applies to a part soldered on a printed circuit board. Note 6. Devices are ESD sensitive. Handling precautions recommended. Note 7. All limits guaranteed by testing on statistical analysis. Note 8. Continuous short circuit may exceed absolute maximum TJ under some conditions. Note 9. The MIC7221 requires 5kΩ pull-up resistor. Partial Functional Diagrams V+ V+ OUT OUT V– V– MIC7211 Push-Pull Output October 2009 MIC7221 Open-Drain Output 4 M9999-100909 Micrel, Inc. MIC7211/7221 Application Information circuits, such as a single-supply zero-crossing detector or a circuit that senses its own supply voltage. The small outline and low supply current (typically 7µA at 5V) of the MIC7211/21 are the primary advantages of these comparators. They have been characterized for 2.2V, 2.7V, 5V, and 10V operation. The comparator must be powered if an input is pulled above the rail, even with current limiting in effect. Figure 2 shows a hypothetical situation where an input is pulled higher than the rail when the power supply is off or not present. Figure 2 also shows external clamp diodes for additional input circuit protection. Discrete clamp diodes can be arbitrarily more robust than the internal clamp diodes. Their 2.2V capability is especially useful in low-battery voltage situations. Low-voltage operation allows longer battery life or deeper discharge capability. Even at 2.2V, the output can drive several logic-gate inputs. At 2.5mA, the output stage voltage drop is guaranteed to not exceed 0.1V. The power supply has been simplified (real power supplies do not have a series output diode); however, this illustrates a common characteristic of most positive-voltage power supplies: they are designed to source, but not sink, current. If the supply is off, or disconnected, there is no limiting voltage for the clamp diode to reference. The input signal can charge the the bypass capacitor, and possibly the filter capacitor, up to the applied input (VIN). This may be high enough to cause a thin-oxide rupture in a CMOS integrated circuit. Outputs The MIC7211 has a push-pull output while the MIC7221 has an open-drain output, otherwise both comparators share a common design. The open-drain MIC7221 output can be pulled up to 10V, even when the supply voltage is as low as 2.2V. Conversely, the output also can be pulled up to voltages that are lower than the positive supply. Logic-level translation is readily facilitated by the ability to pull the open-drain output to voltages above or below the power supply. POSSIBLE DISCONNECT 0V WHEN SUPPLY IS OFF Power Supply Output Although specified short-circuit output current specified for these parts typically exceeds 100mA, their output is not intended to sink or source anywhere near 100mA. The short-circuit rating is only presented as additional information regarding output impedance and may be useful for determining the voltage drop one may experience when driving a given load. V++ V+ VIN (>>V+) VREF 0.1µF RPU RIN R1 VOUT RF Note: 1V ≤ V++ ≤ 10V Figure 2. Avoid This Condition Input Bias Current The low input-bias current (typically 0.5pA) requirement of the MIC7211/21 provides flexibility in the kinds of circuitry and devices that can be directly interfaced. Ideally, the supply for the comparator and the input-producing circuitry should the same or be switched simultaneously. Designs using an amplifier for transducer-to-comparator impedance transformation may be simplified by using the MIC7211/21’s low-input-current requirement to eliminate the amplifier. CMOS circuits, especially logic gates with their totem-pole (push-pull) output stages, generate power supply current spikes (noise) on the supply and/or ground lines. These spikes occur because, for a finite time during switching, both output transistors are partially on allowing “shoot-through current.” Bypass capacitors reduce this noise. Bypass Capacitors Input Signal Levels Input signals may exceed either supply rail by up to 0.2V without phase inversion or other adverse effects. The inputs have internal clamp diodes to the supply pins. Adequate bypassing for the MIC7211 comparator is 0.01µF; in low-noise systems, where this noise may interfere with the functioning or accuracy of nearby circuitry, 0.1µF is recommended. Because the MIC7221 does not have a totem-pole output stage, this spiking is not evident; however, switching a capacitive load can present a similar situation. V+ VIN (±100V) VREF 0.1µF RIN ≥100k R1 Thermal Behavior RF The thermal impedance of a SOT-23-5 package is 325˚C/W. The 5V Electrical Characteristics table shows a maximum voltage drop of 0.1V for a 5mA output current, making the output resistance about 20Ω (R = 0.1/0.005 = 20Ω). Attempting to draw the typical specified output short-circuit current of 150mA (sourcing) can be expected to cause a die temperature rise of 146˚C. (Operating die temperature for ICs should generally not exceed 125˚C.) Using a series resistance is the simplest form of protecting against damage by excessive output current. VOUT Note: RF and R1 control hysteresis (typically, RF >> R1). Figure 1. Driving the Input Beyond the Supply Rails Larger input swings can be accommodated if the input current is limited to 1mA or less. Using a 100k input resistor will allow an input to swing up to 100V beyond either supply rail. Because of the low input bias current of the device, even larger input resistors are practical. See Figure 1. The ability to swing the input beyond either rail facilitates some otherwise difficult October 2009 5 M9999-100909 Micrel, Inc. MIC7211/7221 Package Information SOT-23-5 (M5) October 2009 6 M9999-100909 Micrel, Inc. MIC7211/7221 MICREL INC. 2180 FORTUNE DRIVE SAN JOSE, CA 95131 USA tel + 1 (408) 944-0800 fax + 1 (408) 474-1000 web http://www.micrel.com The information furnished by Micrel in this data sheet is believed to be accurate and reliable. However, no responsibility is assumed by Micrel for its use. Micrel reserves the right to change circuitry and specifications at any time without notification to the customer. Micrel Products are not designed or authorized for use as components in life support appliances, devices or systems where malfunction of a product can reasonably be expected to result in personal injury. Life support devices or systems are devices or systems that (a) are intended for surgical implant into the body or (b) support or sustain life, and whose failure to perform can be reasonably expected to result in a significant injury to the user. A Purchaser’s use or sale of Micrel Products for use in life support appliances, devices or systems is a Purchaser’s own risk and Purchaser agrees to fully indemnify Micrel for any damages resulting from such use or sale. © 2005 Micrel Incorporated. October 2009 7 M9999-100909