LTC1844

Final Electrical Specifications LTC1844 Series 150mA, Micropower, Low Noise, VLDO Linear Regulator May 2003 FEATURES s DESCRIPTIO s s s s s s s s s s s s s s s Very Low Dropout: 90mV at 150mA 30mV at 50mA (LTC1844-3.3) Wide Input Voltage Range: 1.6V to 6.5V Low 35µA Supply Current, Even in Dropout Low Noise: 30µVRMS (10Hz to 100kHz) ±1.75% Voltage Accuracy Over Temperature, Voltage and Current Ranges Fast Transient Response 10nA Supply Current in Shutdown Fixed Output Voltages: 1.5V, 1.8V, 2.5V, 2.8V, 3.3V Adjustable Output Voltage: 1.25V to 6V Output Current Limit Reverse-Battery and Reverse-Current Protection No Protection Diodes Needed Stable with 1µF Output Capacitor Stable with Ceramic Capacitors Short-Circuit and Thermal Overload Protection Low Profile (1mm) SOT-23 Package The LTC®1844 Series are low noise VLDOTM (very low dropout) linear regulators designed for low power/portable applications. These regulators can operate from input voltages as low as 1.6V. Typical output noise is only 30µVRMS and typical dropout for the LTC1844-3.3 is just 90mV at the maximum load current of 150mA, reducing to 30mV at 50mA. The internal P-channel MOSFET pass transistor requires no base current, allowing the device to draw only 35µA during normal operation, independent of the dropout voltage and load current. The quiescent current falls to a negligible 10nA during shutdown. Other features include high output voltage accuracy, excellent transient response, stablity with ultralow ESR ceramic capacitors as small as 1µF, reverse-battery and reverse-current protection, short-circuit and thermal overload protection and output current limiting. The LTC1844 regulators are available in a low profile (1mm) SOT-23 (ThinSOTTM) package. , LTC and LT are registered trademarks of Linear Technology Corporation. VLDO and ThinSOT are trademarks of Linear Technology Corporation. APPLICATIO S s s s s Bluetooth/802.11 Cards PDAs and Notebook Computers Portable Instruments and Battery-Powered Systems Cellular Phones TYPICAL APPLICATIO VIN 3.3V TO 6.5V 1 1µF 3 LTC1844-3.3 Dropout Voltage vs Load Current 120 100 Fixed Voltage Low Noise, VLDO Linear Regulator DROPOUT VOLTAGE (mV) IN OUT LTC1844-3.3 BYP SHDN GND 2 4 0.1µF 1844 TA01 5 1µF VOUT 3.3V 80 60 40 20 0 OFF ON 0 25 Information furnished by Linear Technology Corporation is believed to be accurate and reliable. However, no responsibility is assumed for its use. Linear Technology Corporation makes no representation that the interconnection of its circuits as described herein will not infringe on existing patent rights. U 50 75 100 IOUT (mA) 125 150 1844 TA02 U U 1844ia 1 LTC1844 Series ABSOLUTE AXI U RATI GS (Note 1) Output Short-Circut Duration .......................... Indefinite Operating Junction Temperature Range (Notes 2, 10) .....................................–40°C to 125°C Storage Temperature Range ................. – 65°C to 150°C Lead Temperature (Soldering, 10 sec).................. 300°C Supply Voltage (IN) ....................................... – 7V to 7V Input Voltage SHDN, BYP, ADJ .................................... – 0.3V to 7V Output Voltage OUT ........................................................ – 0.3V to 7V OUT to IN .................................................. – 7V to 7V PACKAGE/ORDER I FOR ATIO TOP VIEW IN 1 GND 2 SHDN 3 4 BYP 5 OUT IN 1 GND 2 SHDN 3 S5 PACKAGE 5-LEAD PLASTIC TSOT-23 S5 PACKAGE 5-LEAD PLASTIC TSOT-23 TJMAX = 150°C, θJA = 250°C/ W, θJC = 90°C/ W SEE THE APPLICATIONS INFORMATION SECTION TJMAX = 150°C, θJA = 250°C/ W, θJC = 90°C/ W SEE THE APPLICATIONS INFORMATION SECTION ORDER PART NUMBER LTC1844ES5-1.5 LTC1844ES5-1.8 LTC1844ES5-2.5 LTC1844ES5-2.8 LTC1844ES5-3.3 S5 PART MARKING LTF1 LTF2 LTF3 LTQK LTF4 ORDER PART NUMBER LTC1844ES5-SD Consult LTC Marketing for parts specified with wider operating temperature ranges. ELECTRICAL CHARACTERISTICS SYMBOL VIN IIN IINSHDN VOUT% PARAMETER Input Voltage Quiescent Current VIN Shutdown Supply Current Regulated Output Voltage (Notes 3, 4, 5) SHDN = VIN CONDITIONS The q denotes specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. VIN = VOUT + 0.5V, unless otherwise noted. (Note 2) MIN q q SHDN = 0V LTC1844-3.3 LTC1844-3.3 LTC1844-2.8 LTC1844-2.8 LTC1844-2.5 LTC1844-2.5 LTC1844-1.8 LTC1844-1.8 VIN = 3.8V to 6.5V, IOUT = 0mA to 150mA VIN = 3.8V to 6.5V, IOUT = 0mA to 150mA VIN = 3.3V to 6.5V, IOUT = 0mA to 150mA VIN = 3.3V to 6.5V, IOUT = 0mA to 150mA VIN = 3.0V to 6.5V, IOUT = 0mA to 150mA VIN = 3.0V to 6.5V, IOUT = 0mA to 150mA VIN = 2.3V to 6.5V, IOUT = 0mA to 150mA VIN = 2.3V to 6.5V, IOUT = 0mA to 150mA 2 U U W WW U W TOP VIEW 5 OUT IN 1 GND 2 4 ADJ BYP 3 TOP VIEW 5 OUT 4 ADJ S5 PACKAGE 5-LEAD PLASTIC TSOT-23 TJMAX = 150°C, θJA = 250°C/ W, θJC = 90°C/ W SEE THE APPLICATIONS INFORMATION SECTION S5 PART MARKING LTE8 ORDER PART NUMBER LTC1844ES5-BYP S5 PART MARKING LTE9 TYP 35 MAX 6.5 55 80 1 1.50 1.75 1.50 1.75 1.50 1.75 1.50 1.75 UNITS V µA µA µA %VOUT %VOUT %VOUT %VOUT %VOUT %VOUT %VOUT %VOUT 1.6 q q q q q 0.01 –1.50 –1.75 –1.50 –1.75 –1.50 –1.75 –1.50 –1.75 1844ia LTC1844 Series ELECTRICAL CHARACTERISTICS SYMBOL PARAMETER CONDITIONS LTC1844-1.5 LTC1844-1.5 LTC1844-1.5 LTC1844-BYP LTC1844-BYP LTC1844-BYP LTC1844-SD LTC1844-SD LTC1844-SD ∆VLNR Line Regulation (Notes 3, 5) LTC1844-3.3 LTC1844-2.8 LTC1844-2.5 LTC1844-1.8 VIN = 2.0V to 6.5V, IOUT = 0mA to 150mA VIN = 2.2V to 6.5V, IOUT = 0mA to 150mA VIN = 2.0V to 6.5V, IOUT = 0mA to 150mA VIN = 1.75V to 6.5V, IOUT = 0mA to 150mA VIN = 2.2V to 6.5V, IOUT = 0mA to 150mA VIN = 1.75V to 6.5V, IOUT = 0mA to 150mA VIN = 1.75V to 6.5V, IOUT = 0mA to 150mA VIN = 2.2V to 6.5V, IOUT = 0mA to 150mA VIN = 1.75V to 6.5V, IOUT = 0mA to 150mA VIN = 3.4V to 6.5V, IL = 1mA VIN = 2.9V to 6.5V, IL = 1mA VIN = 2.6V to 6.5V, IL = 1mA VIN = 2.2V to 6.5V, IL = 1mA VIN = 1.9V to 6.5V, IL = 1mA VIN = 1.9V to 6.5V, IL = 1mA VIN = 2.2V to 6.5V, IL = 1mA VIN = 1.6V to 6.5V, IL = 1mA VIN = 1.6V to 6.5V, IL = 1mA VIN = 2.2V to 6.5V, IL = 1mA VIN = 1.6V to 6.5V, IL = 1mA VIN = 1.6V to 6.5V, IL = 1mA VIN = 2.2V to 6.5V, IL = 1mA VIN = 1.6V to 6.5V, IL = 1mA VIN = 1.6V to 6.5V, IL = 1mA VIN = 3.8V, IOUT = 0mA to 150mA VIN = 3.3V, IOUT = 0mA to 150mA VIN = 3.0V, IOUT = 0mA to 150mA VIN = 2.3V, IOUT = 0mA to 150mA VIN = 2.2V, IOUT = 0mA to 150mA VIN = 2.0V, IOUT = 0mA to 150mA VIN = 2.2V, IOUT = 0mA to 150mA VIN = 1.75V, IOUT = 0mA to 150mA VIN = 2.2V, IOUT = 0mA to 150mA VIN = 1.75V, IOUT = 0mA to 150mA IOUT = 50mA IOUT = 150mA IOUT = 50mA IOUT = 150mA IOUT = 50mA IOUT = 150mA IOUT = 50mA IOUT = 150mA IOUT = 50mA IOUT = 150mA IOUT = 50mA IOUT = 150mA IOUT = 50mA IOUT = 150mA q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q The q denotes specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. VIN = VOUT + 0.5V, unless otherwise noted. (Note 2) MIN –1.50 –2.00 –2.50 –1.50 –1.75 –3.50 –1.50 –1.75 –3.50 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 9 9 9 9 9 9 9 9 9 9 30 90 35 105 45 135 85 230 115 350 45 135 45 135 TYP MAX 1.50 2.00 2.00 1.50 1.75 1.75 1.50 1.75 1.75 20 20 20 20 20 30 20 20 80 20 20 80 20 20 80 20 20 20 20 20 40 20 50 20 50 55 150 60 165 75 200 120 300 160 450 75 200 75 200 UNITS %VOUT %VOUT %VOUT %VOUT %VOUT %VOUT %VOUT %VOUT %VOUT mV mV mV mV mV mV mV mV mV mV mV mV mV mV mV mV mV mV mV mV mV mV mV mV mV mV mV mV mV mV mV mV mV mV mV mV mV mV mV 1844ia LTC1844-1.5 LTC1844-BYP LTC1844-SD ∆VLDR Load Regulation (Notes 3, 5) LTC1844-3.3 LTC1844-2.8 LTC1844-2.5 LTC1844-1.8 LTC1844-1.5 LTC1844-BYP LTC1844-SD ∆VDO Dropout Voltage (Notes 6, 7) LTC1844-3.3 LTC1844-2.8 LTC1844-2.5 LTC1844-1.8 LTC1844-1.5 LTC1844-BYP LTC1844-SD 3 LTC1844 Series ELECTRICAL CHARACTERISTICS SYMBOL ILIM en VSHDN tDELAY TSHDN ∆TSHDN IADJ IIRL PARAMETER Output Current Limit Output Voltage Noise SHDN Input Threshold Shutdown Exit Delay Thermal Shutdown Limit Thermal Shutdown Hysteresis ADJ Pin Bias Current Input Reverse Leakage Current (Notes 3, 8) LTC1844-3.3, LTC1844-2.8, LTC1844-2.5, LTC1844-1.8, LTC1844-1.5, VIN = –5V, VOUT = 0V LTC1844-BYP, LTC1844-SD, VIN = –5V, VOUT = 0V IORL VOSH VRP Output Reverse Leakage Current (Note 9) Start-Up Overshoot Output Ripple Rejection VIN = 0V, VOUT = VOUT(NOMINAL) VIN = 0V, VOUT = VOUT(NOMINAL) RL = 1k, SHDN Rise Time ≤ 1µs (VIN – VOUT) = 1V (Avg), VRIPPLE = 0.5VP-P, fRIPPLE = 120Hz, ILOAD = 100mA q q q q The q denotes specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. VIN = VOUT + 0.5V, unless otherwise noted. (Note 2) CONDITIONS q MIN 160 TYP 350 35 30 MAX UNITS mA µVRMS µVRMS f = 10Hz to 100kHz, CBP = 0.1µF, COUT = 1µF, IL = 150mA f = 10Hz to 100kHz, CBP = 0.1µF, COUT = 10µF, IL = 150mA q 0.35 0.65 70 0.9 100 200 V µs µs °C °C CBP = 0.01µF, COUT = 1µF, No load CBP = 0.01µF, COUT = 1µF, No load q 155 10 30 200 1000 0.01 2 60 100 500 1500 0.1 1.2 nA µA µA µA µA %VOUT dB Note 1: Absolute Maximum Ratings are those values beyond which the life of a device may be impaired. Note 2: The LTC1844 is tested and specified under pulse load conditions such that TJ ≈ TA. The LTC1844E is guaranteed to meet performance specifications from 0°C to 70°C. Specifications over the – 40°C to 125°C operating junction temperature range are assured by design, characterization and correlation with statistical process controls. Note 3: The LTC1844 adjustable versions are tested and specifed for these conditions with the ADJ pin connected to the OUT pin for a VOUT(NOMINAL) of 1.252V. Note 4: Operating conditions are limited by maximum junction temperature. The regulated output voltage specification will not apply for all possible combinations of input voltage and output current. When operating at maximum input voltage, the output current range must be limited. When operating at maximum output current, the input voltage range must be limited. Note 5: The LTC1844’s high precision degrades slightly at high temperatures (TJ > 70°C) with input voltages below 2.2V. The lower output voltage versions have been split into higher and lower accuracy input voltage ranges to reflect this. Note 6: To ensure adequate input supply voltage, the LTC1844 adjustable versions are tested and specified for these conditions with an external resistor divider (two 100k resistors) for an output voltage of 2.504V. The external resistor divider will add a 5µA load on the output. Note 7: Dropout voltage is (VIN – VOUT) when VOUT falls to 100mV below its nominal value measured at VIN = VOUT + 0.5V. For example, the LTC1844-3.3 is tested by measuring the VOUT at VIN = 3.8V, then VIN is lowered until VOUT falls 100mV below the measured value. The difference (VIN – VOUT) is then measured and defined as ∆VDO. Note 8: ADJ pin bias current flows into the ADJ pin. Note 9: Output reverse leakage current is tested with the IN pin grounded and the OUT pin forced to the rated output voltage. Note 10: This IC includes overtemperature protection that is intended to protect the device during momentary overload conditions. Junction temperature will exceed 125°C when overtemperature protection is active. Continuous operation above the specified maximum operating junction temperature may impair device reliability. 1844ia 4 LTC1844 Series PI FU CTIO S IN (Pin 1): Power for LTC1844 and Load. Power is supplied to the device through the IN pin. The IN pin should be locally bypassed to ground if the LTC1844 is more than a few inches away from another source of bulk capacitance. In general, the output impedance of a battery rises with frequency, so it is usually adviseable to include an input bypass capacitor in battery-powered circuits. A capacitor in the range of 0.1µF to 1µF is usually sufficient. The LTC1844 is designed to withstand reverse voltages on the IN pin with respect to both ground and the output pin. In the case of a reversed input, which can happen if a battery is plugged in backwards, the LTC1844 will act as if there is a large resistor in series with its input with only a small amount of current flow. GND (Pin 2): Ground and Heat Sink. Solder to a ground plane or large pad to maximize heat dissipation. SHDN (Pin 3, Fixed and SD Devices): Shutdown, Active Low. This pin is used to put the LTC1844 into shutdown. The SHDN pin current is typically less than 10nA. The SHDN pin cannot be left floating and must be tied to the input pin if not used. If reverse-battery protection is desired, the SHDN pin must be tied to the input pin through a large value resistor (10k to 1M). ADJ (Pin 4, Adjustable Devices): Output Adjust. For the adjustable versions of the LTC1844, this is the input to the error amplifier. It has a typical bias current of 30nA flowing into the pin. The ADJ pin reference voltage is 1.25V referenced to ground. The output voltage range is 1.25V to 6V and is typically set by connecting ADJ to a resistor divider from OUT to GND. See Figure 2. BYP (Pin 4, Fixed/Pin 3, BYP Devices): Noise Bypass. The BYP pin is used to augment the internal noise filter to improve low noise performance. A small low leakage bypass capacitor from this pin to ground will filter the input of the error amplifier to lower the output voltage noise. Any value may be used; larger values will result in lower output noise, but will increase initial power-up time. Shutdown exit delay time after a brief shutdown (