LT3028 Dual 100mA/500mA Low Dropout, Low Noise, Micropower Regulators with Independent Inputs U FEATURES DESCRIPTIO ■ The LT ®3028 is a dual, micropower, low noise, low dropout regulator with independent inputs. With an external 0.01µF bypass capacitor, output noise is a low 20µVRMS over a 10Hz to 100kHz bandwidth. Designed for use in battery-powered systems, the low 30µA quiescent current per output makes it an ideal choice. In shutdown, quiescent current drops to less than 0.1µA. Shutdown control is independent for each output, allowing for flexibility in power management. The device is capable of operating over an input voltage range of 1.8V to 20V. Output 1 can supply 500mA of output current with a dropout voltage of 320mV. The device can supply 100mA of output current from Output 2 with a dropout voltage of 300mV. Quiescent current is well controlled in dropout. The LT3028 regulator is stable with output capacitors as low as 1µF for the 100mA output and 3.3µF for the 500mA output. Small ceramic capacitors can be used without the series resistance required by other regulators. Internal protection circuitry includes reverse-battery protection, current limiting and thermal limiting protection. The device is available as an adjustable device with a 1.22V reference voltage. The LT3028 regulator is available in the thermally enhanced 16-lead TSSOP and 16-lead, low profile (5mm × 3mm × 0.75mm) DFN packages. ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ Low Noise: 20µVRMS (10Hz to 100kHz) Low Quiescent Current: 30µA/Output Independent Inputs Wide Input Voltage Range: 1.8V to 20V Output Current: 100mA/500mA Very Low Shutdown Current: <0.1µA Low Dropout Voltage: 300mV/320mV at 100mA/500mA Adjustable Outputs from 1.22V to 20V Stable with as Low as 1µF/3.3µF Output Capacitor Stable with Aluminum, Tantalum or Ceramic Capacitors Reverse-Battery Protected No Protection Diodes Needed Overcurrent and Overtemperature Protected Tracking/Sequencing Capability Thermally Enhanced 16-Lead TSSOP and 16-Lead (5mm × 3mm) DFN Packages U APPLICATIO S ■ ■ ■ ■ ■ Cellular Phones Pagers Battery-Powered Systems Frequency Synthesizers Wireless Modems Tracking/Sequencing Power Supplies , LTC and LT are registered trademarks of Linear Technology Corporation. Protected by U.S. Patents including 6118263, 6144250. U ■ TYPICAL APPLICATIO 10Hz to 100kHz Output Noise 3.3V/2.5V Low Noise Regulators VIN1 3.7V TO 20V OUT1 IN1 1µF 0.01µF SHDN1 3.3V AT 500mA 20µVRMS NOISE BYP1 ADJ1 OUT2 IN2 1µF VOUT 100µV/DIV 249k LT3028 VIN2 2.9V TO 20V 422k 10µF 0.01µF SHDN2 GND 261k BYP2 ADJ2 10µF 20µVRMS 2.5V AT 100mA 20µVRMS NOISE 3028 TA01b 249k 3028 TA01a 3028f 1 LT3028 W W W AXI U U ABSOLUTE RATI GS (Note 1) IN1, IN2 Pin Voltage .............................................. ±20V OUT1, OUT2 Pin Voltage ....................................... ±20V Input-to-Output Differential Voltage ....................... ±20V ADJ1, ADJ2 Pin Voltage ......................................... ±7V BYP1, BYP2 Pin Voltage ....................................... ±0.6V SHDN1, SHDN2 Pin Voltage ................................. ±20V Output Short-Circut Duration .......................... Indefinite Operating Junction Temperature Range (Note 2) ............................................ – 40°C to 125°C Storage Temperature Range FE Package ....................................... – 65°C to 150°C DHC Package .................................... – 65°C to 125°C Lead Temperature (Soldering, 10 sec).................. 300°C U U W PACKAGE/ORDER I FOR ATIO TOP VIEW GND 1 16 GND BYP1 2 15 ADJ1 OUT1 3 14 SHDN1 OUT1 4 GND 5 12 IN2 OUT2 6 11 SHDN2 BYP2 7 10 ADJ2 GND 8 9 17 13 IN1 GND FE PACKAGE 16-LEAD PLASTIC TSSOP TJMAX = 150°C, θJA = 38°C/ W, θJC = 8°C/ W EXPOSED PAD (PIN 17) IS GND MUST BE SOLDERED TO PCB ORDER PART NUMBER LT3028EFE LT3028IFE FE PART MARKING 3028EFE 3028IFE ORDER PART NUMBER TOP VIEW BYP1 1 16 ADJ1 NC 2 15 SHDN1 OUT1 3 14 IN1 OUT1 4 GND 5 12 IN2 OUT2 6 11 IN2 OUT2 7 10 SHDN2 BYP2 8 9 17 LT3028EDHC LT3028IDHC 13 IN1 DHC PART MARKING ADJ2 3028 3028I DHC PACKAGE 16-LEAD (5mm × 3mm) PLASTIC DFN TJMAX = 125°C, θJA = 40°C/ W, θJC = 10°C/ W EXPOSED PAD (PIN 17) IS GND MUST BE SOLDERED TO PCB Consult factory for parts specified with wider operating temperature ranges. ELECTRICAL CHARACTERISTICS The ● denotes specifications which apply over the full operating temperature range, otherwise specifications are TA = 25°C. (Note 2) PARAMETER CONDITIONS MIN Minimum Input Voltage (Notes 3, 10) Output 2, ILOAD = 100mA Output 1, ILOAD = 500mA ● ● ADJ1, ADJ2 Pin Voltage (Notes 3, 4) VIN = 2V, ILOAD = 1mA Output 2, 2.3V < VIN2 < 20V, 1mA < ILOAD < 100mA Output 1, 2.3V < VIN1 < 20V, 1mA < ILOAD < 500mA ● ● Line Regulation (Note 3) ∆VIN = 2V to 20V, ILOAD = 1mA ● Load Regulation (Note 3) Output 2, VIN2 = 2.3V, ∆ILOAD = 1mA to 100mA VIN2 = 2.3V, ∆ILOAD = 1mA to 100mA ● Output 1, VIN1 = 2.3V, ∆ILOAD = 1mA to 500mA VIN1 = 2.3V, ∆ILOAD = 1mA to 500mA ● 1.205 1.190 1.190 TYP MAX UNITS 1.8 1.8 2.3 2.3 V V 1.220 1.220 1.220 1.235 1.250 1.250 V V V 1 10 mV 1 12 25 mV mV 1 12 25 mV mV 3028f 2 LT3028 ELECTRICAL CHARACTERISTICS The ● denotes specifications which apply over the full operating temperature range, otherwise specifications are TA = 25°C. (Note 2) PARAMETER CONDITIONS Dropout Voltage (Output 2) VIN2 = VOUT2(NOMINAL) (Notes 5, 6, 10) ILOAD = 1mA ILOAD = 1mA ● ILOAD = 10mA ILOAD = 10mA ● ILOAD = 50mA ILOAD = 50mA ● ILOAD = 100mA ILOAD = 100mA ● ILOAD = 10mA ILOAD = 10mA ● ILOAD = 50mA ILOAD = 50mA ● ILOAD = 100mA ILOAD = 100mA ● ILOAD = 500mA ILOAD = 500mA ● GND Pin Current (Output 2) VIN2 = VOUT2(NOMINAL) (Notes 5, 7) ILOAD = 0mA ILOAD = 1mA ILOAD = 10mA ILOAD = 50mA ILOAD = 100mA GND Pin Current (Output 1) VIN1 = VOUT1(NOMINAL) (Notes 5, 7) ILOAD = 0mA ILOAD = 1mA ILOAD = 50mA ILOAD = 100mA ILOAD = 250mA ILOAD = 500mA Output Voltage Noise COUT = 10µF, CBYP = 0.01µF, ILOAD = Full Current, BW = 10Hz to 100kHz 20 ADJ1/ADJ2 Pin Bias Current ADJ1, ADJ2 (Notes 3, 8) 30 100 nA Shutdown Threshold VOUT = Off to On VOUT = On to Off ● ● 0.80 0.65 1.4 V V SHDN1/SHDN2 Pin Current (Note 9) VSHDN1, VSHDN2 = 0V VSHDN1, VSHDN2 = 20V ● ● 0 1 0.5 3.0 µA µA Quiescent Current in Shutdown VIN = 6V, VSHDN1 = 0V, VSHDN2 = 0V 0.01 0.1 µA Ripple Rejection VIN = 2.72V (Avg), VRIPPLE = 0.5VP-P, fRIPPLE = 120Hz, ILOAD = Full Current Current Limit Output 2, VIN2 = 7V, VOUT2 = 0V VIN2 = 2.3V, ∆VOUT2 = – 0.1V ● 110 Output 1, VIN1 = 7V, VOUT1 = 0V VIN1 = 2.3V, ∆VOUT1 = – 0.1V ● 520 VIN = – 20V, VOUT = 0V ● Dropout Voltage (Output 1) VIN1 = VOUT1(NOMINAL) (Notes 5, 6, 10) Input Reverse Leakage Current Note 1: Absolute Maximum Ratings are those values beyond which the life of a device may be impaired. Note 2: The LT3028 regulator is tested and specified under pulse load conditions such that TJ ≈ TA. The LT3028E is guaranteed to meet performance specifications from 0°C to 125°C junction temperature. Specifications over the – 40°C to 125°C operating junction temperature MIN TYP MAX UNITS 0.10 0.15 0.19 V V 0.17 0.22 0.29 V V 0.24 0.31 0.40 V V 0.30 0.35 0.45 V V 0.12 0.19 0.25 V V 0.17 0.22 0.32 V V 0.21 0.28 0.34 V V 0.32 0.37 0.47 V V ● ● ● ● ● 25 60 230 1 2.2 50 95 400 2 4 µA µA µA mA mA ● ● ● ● ● ● 30 65 1 2 5 10 75 120 1.6 3 8 16 µA µA mA mA mA mA 0.25 55 µVRMS 65 dB 500 mA mA 1.3 A mA 1 mA range are assured by design, characterization and correlation with statistical process controls. The LT3028I is guaranteed and tested over the full – 40°C to 125°C operating junction temperature range. Note 3: The LT3028 is tested and specified for these conditions with the ADJ1/ADJ2 pin connected to the corresponding OUT1/OUT2 pin. 3028f 3 LT3028 ELECTRICAL CHARACTERISTICS 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: To satisfy requirements for minimum input voltage, the LT3028 is tested and specified for these conditions with an external resistor divider (two 250k resistors) for an output voltage of 2.44V. The external resistor divider will add a 5µA DC load on the output. Note 6: Dropout voltage is the minimum input to output voltage differential needed to maintain regulation at a specified output current. In dropout, the output voltage will be equal to: VIN – VDROPOUT. Note 7: GND pin current is tested with VIN = 2.44V and a current source load. This means the device is tested while operating in its dropout region or at the minimum input voltage specification. This is the worst-case GND pin current. The GND pin current will decrease slightly at higher input voltages. Total GND pin current is equal to the sum of GND pin currents from Output 1 and Output 2. Note 8: ADJ1 and ADJ2 pin bias current flows into the pin. Note 9: SHDN1 and SHDN2 pin current flows into the pin. Note 10: For the LT3028 dropout voltage will be limited by the minimum input voltage specification under some output voltage/load conditions. See the curve of Minimum Input Voltage in the Typical Performance Characteristics. U W TYPICAL PERFOR A CE CHARACTERISTICS Output 2 Guaranteed Dropout Voltage 500 450 450 450 400 400 400 TJ = 125°C 300 250 TJ = 25°C 200 150 = TEST POINTS DROPOUT VOLTAGE (mV) 350 TJ ≤ 125°C 350 300 TJ ≤ 25°C 250 200 150 350 250 150 100 50 50 50 0 10 20 30 40 50 60 70 80 90 100 OUTPUT CURRENT (mA) 3028 G01 300 250 TJ = 25°C 200 150 100 50 0 Output 1 Dropout Voltage = TEST POINTS 450 450 400 DROPOUT VOLTAGE (mV) GUARANTEED DROPOUT VOLTAGE (mV) 350 TJ ≤ 125°C 350 300 TJ ≤ 25°C 250 200 150 50 100 150 200 250 300 350 400 450 500 OUTPUT CURRENT (mA) 3028 G04 300 200 150 50 3028 G05 IL = 100mA IL = 50mA 250 100 50 100 150 200 250 300 350 400 450 500 OUTPUT CURRENT (mA) IL = 250mA 350 50 0 IL = 500mA 400 100 0 0 125 100 500 500 TJ = 125°C 50 25 0 75 TEMPERATURE (°C) 3028 G03 Output 1 Guaranteed Dropout Voltage 500 400 IL = 1mA 3028 G02 Output 1 Typical Dropout Voltage 450 IL = 10mA 0 –50 –25 0 10 20 30 40 50 60 70 80 90 100 OUTPUT CURRENT (mA) IL = 50mA 200 100 0 IL = 100mA 300 100 0 DROPOUT VOLTAGE (mV) Output 2 Dropout Voltage 500 500 DROPOUT VOLTAGE (mV) DROPOUT VOLTAGE (mV) Output 2 Typical Dropout Voltage 0 –50 –25 IL = 10mA 50 25 0 75 TEMPERATURE (°C) IL = 1mA 100 125 3028 G06 3028f 4 LT3028 U W TYPICAL PERFOR A CE CHARACTERISTICS ADJ1 or ADJ2 Pin Voltage 45 1.235 40 35 VSHDN = VIN 30 25 20 15 TJ = 25°C 35 RL = 250k IL = 1mA 1.230 1.225 1.220 1.215 1.210 10 5 VIN = 6V RL = 250k, IL = 5µA 0 0 25 –50 –25 50 75 100 125 25 50 75 RL = 24.4Ω IL = 50mA* 0.75 0.25 2 3 4 5 6 7 INPUT VOLTAGE (V) 8 1000 2.00 1.75 1.50 1.25 1.00 0.75 10 0 12 TJ = 25°C VIN = VSHDN *FOR VOUT = 1.22V 400 RL = 122Ω IL = 10mA* 200 RL = 1.22k IL = 1mA* 4 RL = 12.2Ω IL = 100mA* 1 2 3 4 5 6 7 INPUT VOLTAGE (V) 8 9 10 SHDN1 or SHDN2 Pin Threshold (On-to-Off) 1.0 VIN = VOUT(NOMINAL) + 1V TJ = 25°C 0.9 SHDN PIN THRESHOLD (V) GND PIN CURRENT (mA) RL = 4.07Ω IL = 300mA* 0 3028 G12 10 RL = 2.44Ω IL = 500mA* 2 600 Output 1 GND Pin Current vs ILOAD 12 6 TJ = 25°C VIN = VSHDN *FOR VOUT = 1.22V 3028 G11 Output 1 GND Pin Current 8 800 0 10 20 30 40 50 60 70 80 90 100 OUTPUT CURRENT (mA) 3028 G10 10 RL = 24.4Ω IL = 50mA* 0.25 9 6 8 10 12 14 16 18 20 INPUT VOLTAGE (V) Output 1 GND Pin Current 0 1 4 1200 0.50 RL = 122Ω IL = 10mA* 0 0 2 3028 G09 GND PIN CURRENT (µA) GND PIN CURRENT (mA) GND PIN CURRENT (mA) 1.50 RL = 1.22k IL = 1mA* 0 VIN = VOUT(NOMINAL) + 1V TJ = 25°C 2.25 RL = 12.2Ω IL = 100mA* 0.50 125 Output 2 GND Pin Current vs ILOAD TJ = 25°C *FOR VOUT = 1.22V 1.00 100 VSHDN = 0V 3028 G08 2.50 1.25 10 TEMPERATURE (°C) 2.50 1.75 15 0 Output 2 GND Pin Current 2.00 20 1.200 –50 –25 3028 G07 2.25 25 5 0 VSHDN = VIN 30 1.205 TEMPERATURE (°C) GND PIN CURRENT (mA) Quiescent Current (Per Output) 40 QUIESCENT CURRENT (µA) 1.240 ADJ PIN VOLTAGE (V) QUIESCENT CURRENT (µA) Quiescent Current (Per Output) 50 8 6 4 2 IL = 1mA 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0 0 1 2 3 4 5 6 7 INPUT VOLTAGE (V) 0 8 9 10 3028 G13 0 50 100 150 200 250 300 350 400 450 500 OUTPUT CURRENT (mA) 3028 G14 0 –50 –25 50 25 0 75 TEMPERATURE (°C) 100 125 3028 G15 3028f 5 LT3028 U W TYPICAL PERFOR A CE CHARACTERISTICS SHDN1 or SHDN2 Pin Input Current 1.0 0.9 0.9 IL = FULL 0.8 0.7 0.6 IL = 1mA 0.5 0.4 0.3 0.2 0.1 SHDN1 or SHDN2 Pin Input Current 1.4 TJ = 25°C SHDN PIN INPUT CURRENT (µA) 1.0 SHDN PIN INPUT CURRENT (µA) SHDN PIN THRESHOLD (V) SHDN1 or SHDN2 Pin Threshold (Off-to-On) 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0 –50 –25 0 50 25 0 75 TEMPERATURE (°C) 100 125 0 1 2 3 4 5 6 7 8 SHDN PIN VOLTAGE (V) 9 3028 G16 350 60 50 40 30 20 300 0.2 50 25 0 75 TEMPERATURE (°C) 125 VIN2 = 7V VOUT2 = 0V 300 200 150 100 50 250 200 150 100 50 0 125 100 Output 2 Current Limit 350 250 10 0 4 3 2 5 INPUT VOLTAGE (V) 1 7 6 0 –50 –25 50 25 0 75 TEMPERATURE (°C) 3028 G20 3028 G19 Output 1 Current Limit 100 125 3028 G21 Output 1 Current Limit 1.0 1.2 0.8 1.0 VOUT1 = 0V 0.9 TJ = 25°C 0.7 CURRENT LIMIT (A) CURRENT LIMIT (A) 0.4 3028 G18 CURRENT LIMIT (mA) SHORT-CIRCUIT CURRENT (mA) ADJ PIN BIAS CURRENT (nA) 70 100 0.6 0 –50 –25 10 VOUT2 = 0V TJ = 25°C 90 50 25 0 75 TEMPERATURE (°C) 0.8 Output 2 Current Limit ADJ1 or ADJ2 Pin Bias Current 0 –50 –25 1.0 3028 G17 100 80 VSHDN = 20V 1.2 0.6 0.5 0.4 0.3 0.2 VIN1 = 7V VOUT1 = 0V 0.8 0.6 0.4 0.2 0.1 0 0 1 4 3 2 5 INPUT VOLTAGE (V) 6 7 3028 G22 0 –50 –25 50 25 0 75 TEMPERATURE (°C) 100 125 3028 G23 3028f 6 LT3028 U W TYPICAL PERFOR A CE CHARACTERISTICS Output 2 Input Ripple Rejection 80 70 70 60 60 50 COUT = 10µF 40 30 COUT = 1µF 20 I = 100mA L V = 2.3V + 50mVRMS RIPPLE 10 CIN2 = 0 BYP TJ = 25°C 0 0.1 0.01 1 10 FREQUENCY (kHz) 100 Output 2 Input Ripple Rejection 80 CBYP = 0.01µF 70 CBYP = 1000pF 50 CBYP = 100pF 40 30 20 I = 100mA L VIN2 = 2.3V + 50mVRMS RIPPLE 10 C OUT = 10µF TJ = 25°C 0 0.1 0.01 1 10 FREQUENCY (kHz) 1000 100 1000 60 50 40 30 20 VIN2 = VOUT2(NOMINAL) + 1V + 0.5VP-P RIPPLE 10 AT f = 120Hz IL = 50mA 0 0 50 25 –50 –25 3028 G27 Output 1 Input Ripple Rejection 70 66 60 64 40 30 IL = 500mA 20 V = V IN1 OUT1(NOMINAL) + COUT = 4.7µF 1V + 50mVRMS RIPPLE 10 C BYP = 0 TJ = 25°C 0 100 100k 10 1k 10k 1M FREQUENCY (Hz) RIPPLE REJECTION (dB) 68 70 CBYP = 0.01µF RIPPLE REJECTION (dB) 80 50 50 CBYP = 1000pF CBYP = 100pF 40 30 IL = 500mA 20 V = V IN1 OUT1(NOMINAL) + 1V + 50mVRMS RIPPLE 10 COUT = 10µF TJ = 25°C 0 100 10 1k 10k FREQUENCY (Hz) 62 60 58 56 54 100k VIN1 = VOUT1(NOMINAL) + 1V + 0.5VP-P RIPPLE AT f = 120Hz IL = 500mA 52 –50 –25 1M 0 50 25 75 100 125 TEMPERATURE (°C) 3028 G30 3028 G29 Output 2 Minimum Input Voltage 3028 G31 Output 1 Minimum Input Voltage 2.50 2.5 VOUT2 = 1.22V VOUT1 = 1.22V 2.25 MINIMUM INPUT VOLTAGE (V) MINIMUM INPUT VOLTAGE (V) 125 Output 1 Ripple Rejection 80 COUT = 10µF 100 3028 G28 Output 1 Input Ripple Rejection 60 75 TEMPERATURE (°C) 3028 G26 RIPPLE REJECTION (dB) RIPPLE REJECTION (dB) 80 RIPPLE REJECTION (dB) RIPPLE REJECTION (dB) Output 2 Input Ripple Rejection 2.0 IL = 100mA 1.5 IL = 50mA 1.0 0.5 2.00 IL = 500mA 1.75 1.50 IL = 1mA 1.25 1.00 0.75 0.50 0.25 0 –50 –25 50 25 0 75 TEMPERATURE (°C) 100 125 3028 G32 0 –50 –25 50 25 0 75 TEMPERATURE (°C) 100 125 3028 G33 3028f 7 LT3028 U W TYPICAL PERFOR A CE CHARACTERISTICS Channel-to-Channel Isolation Channel-to-Channel Isolation Output 2 Load Regulation 0 90 –1 CHANNEL 2 80 –2 VOUT1 20mV/DIV 70 LOAD REGULATION (mV) CHANNEL-TO-CHANNEL ISOLATION (dB) 100 CHANNEL 1 60 50 VOUT2 20mV/DIV 40 GIVEN CHANNEL IS TESTED 30 WITH 50mVRMS SIGNAL ON OPPOSING CHANNEL, BOTH 20 CHANNELS DELIVERING FULL 10 CURRENT TJ = 25°C 0 100 1k 10k 10 FREQUENCY (Hz) –3 –4 –5 –6 –7 –8 100k COUT1 = 22µF 50µs/DIV COUT2 = 10µF CBYP1 = CBYP2 = 0.01µF ∆IL1 = 50mA TO 500mA ∆IL2 = 10mA TO 100mA VIN = 6V, VOUT1 = VOUT2 = 5V 1M 3028 G50 –9 ∆IL = 1mA TO 100mA –10 0 50 75 25 –50 –25 TEMPERATURE (°C) 100 3028 G34 3028 G35 Output 1 Load Regulation ∆IL = 1mA TO 500mA 0 –5 0 25 50 75 100 125 COUT = 10µF CBYP = 0 IL = FULL LOAD TJ = 25°C VOUT SET FOR 5V 1 VOUT =VADJ 0.1 0.01 0.01 TEMPERATURE (°C) 0.1 1 10 FREQUENCY (kHz) OUTPUT NOISE (µVRMS) 120 100 OUTPUT 2 80 OUTPUT 1 60 VOUT = 1.22V OUTPUT 2 40 OUTPUT 1 20 0 100 1000 10000 CBYP (pF) 3028 G39 CBYP = 1000pF CBYP = 100pF VOUT =VADJ 0.1 CBYP = 0.01µF 0.01 0.01 0.1 1 10 FREQUENCY (kHz) 160 140 100 VOUT2 SET FOR 5V 80 60 VOUT2 =VADJ2 40 0 0.01 100 Output 1 RMS Output Noise vs Load Current (10Hz to 100kHz) COUT2 = 10µF 140 TJ = 25°C CBYP = 0 CBYP = 0.01µF 120 20 10 VOUT SET FOR 5V 3028 G38 160 OUTPUT NOISE (µVRMS) COUT = 10µF IL = FULL LOAD fBW = 10Hz TO 100kHz TJ = 25°C COUT = 10µF IL = FULL LOAD TJ = 25°C 1 Output 2 RMS Output Noise vs Load Current (10Hz to 100kHz) RMS Output Noise vs Bypass Capacitor VOUT = 5V 100 10 3028 G37 3028 G36 140 Output Noise Spectral Density VOUT2 SET FOR 5V 120 COUT1 = 10µF TJ = 25°C CBYP = 0 CBYP = 0.01µF 100 80 VOUT1 SET FOR 5V 60 VOUT1 = VADJ1 40 VOUT1 SET FOR 5V 20 VOUT2 =VADJ2 0.1 1 10 LOAD CURRENT (mA) OUTPUT NOISE (µVRMS) –10 –50 –25 10 OUTPUT NOISE SPECTRAL DENSITY (µV/√Hz) Output Noise Spectral Density OUTPUT NOISE SPECTRAL DENSITY (µV/√Hz) LOAD REGULATION (mV) 5 125 100 3028 G40 0 0.01 VOUT1 = VADJ1 0.1 10 100 1 LOAD CURRENT (mA) 1000 3028 G41 3028f 8 LT3028 U W TYPICAL PERFOR A CE CHARACTERISTICS 10Hz to 100kHz Output Noise CBYP = 0pF 10Hz to 100kHz Output Noise CBYP = 1000pF 10Hz to 100kHz Output Noise CBYP = 100pF VOUT 100µV/DIV VOUT 100µV/DIV 1ms/DIV COUT = 10µF IL = FULL LOAD VOUT SET FOR 5V 3028 G42 10Hz to 100kHz Output Noise CBYP = 0.01µF VIN2 = 6V, VOUT2 SET FOR 5V 0.2 CIN2 = 10µF COUT2 = 10µF 0.1 T = 25°C J 0 –0.1 –0.2 LOAD CURRENT (mA) OUTPUT VOLTAGE DEVIATION (V) LOAD CURRENT (mA) 3028 G45 100 50 0 0 400 800 1200 TIME (µs) 1600 2000 VIN2 = 6V, VOUT2 SET FOR 5V 0.04 CIN2 = 10µF COUT2 = 10µF 0.02 T = 25°C J 0 –0.02 –0.04 100 50 0 0 20 40 60 80 100 120 140 160 180 200 TIME (µs) 3028 G46 OUTPUT VOLTAGE DEVIATION (V) –0.2 –0.4 VIN1 = 6V, VOUT1 SET FOR 5V 0.10 CIN1 = 10µF COUT1 = 10µF 0.05 T = 25°C J 0 –0.05 –0.10 LOAD CURRENT (mA) OUTPUT VOLTAGE DEVIATION (V) LOAD CURRENT (mA) VIN1 = 6V, VOUT1 SET FOR 5V 0.4 CIN1 = 10µF COUT1 = 10µF 0.2 T = 25°C J 0 600 400 200 0 200 400 600 TIME (µs) 800 3028 G47 Output 1 Transient Response CBYP = 0.01µF Output 1 Transient Response CBYP = 0pF 0 3028 G44 Output 2 Transient Response CBYP = 0.01µF Output 2 Transient Response CBYP = 0pF VOUT 100µV/DIV COUT = 10µF 1ms/DIV IL = FULL LOAD VOUT SET FOR 5V COUT = 10µF 1ms/DIV IL = FULL LOAD VOUT SET FOR 5V 3028 G43 OUTPUT VOLTAGE DEVIATION (V) 1ms/DIV COUT = 10µF IL = FULL LOAD VOUT SET FOR 5V VOUT 100µV/DIV 1000 3028 G48 600 400 200 0 0 10 20 30 40 50 60 70 80 90 100 TIME (µs) 3028 G49 3028f 9 LT3028 U U U PI FU CTIO S (DFN Package)/(TSSOP Package) GND (Pins 5, 17)/(Pins 1, 5, 8, 9, 16, 17): Ground. The Exposed Pad must be soldered to PCB ground for optimum thermal performance. ADJ1/ADJ2 (Pins 16/9)/(Pins 15/10): Adjust Pin. These are the inputs to the error amplifiers. These pins are internally clamped to ±7V. They have a bias current of 30nA which flows into the pin (see curve of ADJ1/ADJ2 Pin Bias Current vs Temperature in the Typical Performance Characteristics section). The ADJ1 and ADJ2 pin voltage is 1.22V referenced to ground and the output voltage range is 1.22V to 20V. BYP1/BYP2 (Pins 1/8)/(Pins 2/7): Bypass. The BYP1/BYP2 pins are used to bypass the reference of the LT3028 regulator to achieve low noise performance from the regulator. The BYP1/BYP2 pins are clamped internally to ±0.6V (one VBE) from ground. A small capacitor from the corresponding output to this pin will bypass the reference to lower the output voltage noise. A maximum value of 0.01µF can be used for reducing output voltage noise to a typical 20µVRMS over a 10Hz to 100kHz bandwidth. If not used, this pin must be left unconnected. OUT1/OUT2 (Pins 3, 4/6, 7)/(Pins 3, 4/6): Output. The outputs supply power to the loads. A minimum output capacitor of 1µF is required to prevent oscillations on Output 2; Output 1 requires a minimum of 3.3µF. Larger output capacitors will be required for applications with large transient loads to limit peak voltage transients. See the Applications Information section for more information on output capacitance and reverse output characteristics. SHDN1/SHDN2 (Pins 15/10)/(Pins 14/11): Shutdown. The SHDN1/SHDN2 pins are used to put the corresponding output of the LT3028 regulator into a low power shutdown state. The output will be off when the pin is pulled low. The SHDN1/SHDN2 pins can be driven either by 5V logic or open-collector logic with pull-up resistors. The pull-up resistors are required to supply the pull-up current of the open-collector gates, normally several microamperes, and the SHDN1/SHDN2 pin current, typically 1µA. If unused, the pin must be connected to VIN. The device will not function if the SHDN1/SHDN2 pins are not connected. IN1/IN2 (Pins 13, 14/11, 12)/(Pins 13/12): Inputs. Power is supplied to the device through the IN pins. A bypass capacitor is required on these pins if the device is more than six inches away from the main input filter capacitor. In general, the output impedance of a battery rises with frequency, so it is advisable to include a bypass capacitor in battery-powered circuits. A bypass capacitor in the range of 1µF to 10µF is sufficient. The LT3028 regulator is designed to withstand reverse voltages on the IN pins with respect to ground and the OUT pins. In the case of a reverse input, which can happen if a battery is plugged in backwards, the device will act as if there is a diode in series with its input. There will be no reverse current flow into the regulator and no reverse voltage will appear at the load. The device will protect both itself and the load. U W U U APPLICATIO S I FOR ATIO The LT3028 is a dual 100mA/500mA low dropout regulator with independent inputs, micropower quiescent current, and shutdown. The device is capable of supplying 100mA from Output 2 at a dropout voltage of 300mV. Output 1 delivers 500mA at a dropout voltage of 320mV. The two regulators have common GND pins and are thermally coupled, however, the two inputs and outputs of the LT3028 operate independently. They can be shut down independently and a fault condition on one output will not affect the other output electrically. Output voltage noise can be lowered to 20µVRMS over a 10Hz to 100kHz bandwidth with the addition of a 0.01µF reference bypass capacitor. Additionally, the reference bypass capacitor will improve transient response of the regulator, lowering the settling time for transient load conditions. The low operating quiescent current (30µA per output) drops to less 3028f 10 LT3028 U W U U APPLICATIO S I FOR ATIO than 1µA in shutdown. In addition to the low quiescent current, the LT3028 regulator incorporates several protection features which make it ideal for use in batterypowered systems. The device is protected against reverse input voltages. Additionally, in dual supply applications where the regulator load is returned to a negative supply, the output can be pulled below ground by as much as 20V and still allow the device to start and operate. Adjustable Operation The LT3028 has an output voltage range of 1.22V to 20V. The output voltage is set by the ratio of two external resistors as shown in Figure 1. The device servos the output to maintain the corresponding ADJ pin voltage at 1.22V referenced to ground. The current in R1 is then equal to 1.22V/R1 and the current in R2 is the current in R1 plus the ADJ pin bias current. The ADJ pin bias current, 30nA at 25°C, flows through R2 into the ADJ pin. The output voltage can be calculated using the formula in Figure 1. The value of R1 should be no greater than 250k to minimize errors in the output voltage caused by the ADJ pin bias current. Note that in shutdown the output is turned off and the divider current will be zero. Curves of ADJ Pin Voltage vs Temperature and ADJ Pin Bias Current vs Temperature appear in the Typical Performance Characteristics. The device is tested and specified with the ADJ pin tied to the corresponding OUT pin for an output voltage of 1.22V. Specifications for output voltages greater than 1.22V will be proportional to the ratio of the desired output voltage to 1.22V: VOUT/1.22V. For example, load regulation on Output 2 for an output current change of 1mA to 100mA OUT1/OUT2 VIN VOUT + IN1/IN2 R2 LT3028 ADJ1/ADJ2 GND R1 ⎛ R2 ⎞ VOUT = 1.22V ⎜ 1 + ⎟ + (IADJ )(R2) ⎝ R1⎠ VADJ = 1.22V IADJ = 30nA AT 25°C OUTPUT RANGE = 1.22V TO 20 V 3024 F01 Figure 1. Adjustable Operation is –1mV typical at VOUT = 1.22V. At VOUT = 12V, load regulation is: (12V/1.22V)(–1mV) = – 9.8mV Bypass Capacitance and Low Noise Performance The LT3028 regulator may be used with the addition of a bypass capacitor from VOUT to the corresponding BYP pin to lower output voltage noise. A good quality low leakage capacitor is recommended. This capacitor will bypass the reference of the regulator, providing a low frequency noise pole. The noise pole provided by this bypass capacitor will lower the output voltage noise to as low as 20µVRMS with the addition of a 0.01µF bypass capacitor. Using a bypass capacitor has the added benefit of improving transient response. With no bypass capacitor and a 10µF output capacitor, a 10mA to 100mA load step on Output 2 will settle to within 1% of its final value in less than 100µs. With the addition of a 0.01µF bypass capacitor, the output will stay within 1% for the same load step. Both outputs exhibit this improvement in transient response (see Transient Reponse in Typical Performance Characteristics section). However, regulator start-up time is inversely proportional to the size of the bypass capacitor, slowing to 15ms with a 0.01µF bypass capacitor and 10µF output capacitor. Output Capacitance and Transient Response The LT3028 regulator is designed to be stable with a wide range of output capacitors. The ESR of the output capacitor affects stability, most notably with small capacitors. A minimum output capacitor of 1µF with an ESR of 3Ω or less is recommended for Output 2 to prevent oscillations. A minimum output capacitor of 3.3µF with an ESR of 3Ω or less is recommended for Output 1. The LT3028 is a micropower device and output transient response will be a function of output capacitance. Larger values of output capacitance decrease the peak deviations and provide improved transient response for larger load current changes. Bypass capacitors, used to decouple individual components powered by the LT3028, will increase the effective output capacitor value. With larger capacitors 3028f 11 LT3028 U W U U APPLICATIO S I FOR ATIO used to bypass the reference (for low noise operation), larger values of output capacitors are needed. For 100pF of bypass capacitance on Output 2, 2.2µF of output capacitor is recommended. With a 330pF bypass capacitor or larger on this output, a 3.3µF output capacitor is recommended. For Output 1, 4.7µF of output capacitor is recommended for 100pF of bypass capacitance. With 1000pF or larger bypass capacitor on this output, a 6.8µF output capacitor is recommended. The shaded region of Figures 2 and 3 define the regions over which the LT3028 regulator is stable. The minimum ESR needed is defined by the amount of bypass capacitance used, while the maximum ESR is 3Ω. Extra consideration must be given to the use of ceramic capacitors. Ceramic capacitors are manufactured with a variety of dielectrics, each with different behavior across temperature and applied voltage. The most common dielectrics used are Z5U, Y5V, X5R and X7R. The Z5U and Y5V dielectrics are good for providing high capacitances in a small package, but exhibit strong voltage and temperature coefficients as shown in Figures 4 and 5. When used with a 5V regulator, a 10µF Y5V capacitor can exhibit an effective value as low as 1µF to 2µF over the operating temperature range. The X5R and X7R dielectrics result in more stable characteristics and are more suitable for use as the output capacitor. The X7R type has better stability across temperature, while the X5R is less expensive and is available in higher values. 4.0 4.0 3.5 3.5 3.0 3.0 STABLE REGION STABLE REGION 2.5 ESR (Ω) ESR (Ω) 2.5 2.0 CBYP = 0 CBYP = 100pF CBYP = 330pF CBYP > 3300pF 1.5 1.0 0.5 2.0 CBYP = 0 CBYP = 100pF 1.5 CBYP = 330pF CBYP ≥ 1000pF 1.0 0.5 0 0 1 1 3 2 4 5 6 7 8 9 10 OUTPUT CAPACITANCE (µF) 3 2 4 5 6 7 8 9 10 OUTPUT CAPACITANCE (µF) 3028 F03 3028 F02 Figure 2. Output 2 Stability Figure 3. Output 1 Stability 40 20 BOTH CAPACITORS ARE 16V, 1210 CASE SIZE, 10µF 20 X5R CHANGE IN VALUE (%) CHANGE IN VALUE (%) 0 –20 –40 –60 Y5V –80 –100 X5R 0 –20 –40 Y5V –60 –80 0 2 4 8 6 10 12 DC BIAS VOLTAGE (V) 14 16 3028 F04 Figure 4. Ceramic Capacitor DC Bias Characteristics BOTH CAPACITORS ARE 16V, 1210 CASE SIZE, 10µF –100 50 25 75 –50 –25 0 TEMPERATURE (°C) 100 125 3028 F05 Figure 5. Ceramic Capacitor Temperature Characteristics 3028f 12 LT3028 U W U U APPLICATIO S I FOR ATIO Voltage and temperature coefficients are not the only sources of problems. Some ceramic capacitors have a piezoelectric response. A piezoelectric device generates voltage across its terminals due to mechanical stress, similar to the way a piezoelectric accelerometer or microphone works. For a ceramic capacitor the stress can be induced by vibrations in the system or thermal transients. The resulting voltages produced can cause appreciable amounts of noise, especially when a ceramic capacitor is used for noise bypassing. A ceramic capacitor produced Figure 6’s trace in response to light tapping from a pencil. Similar vibration induced behavior can masquerade as increased output voltage noise. COUT = 10µF CBYP = 0.01µF ILOAD = 100mA For continuous normal conditions, the maximum junction temperature rating of 125°C must not be exceeded. It is important to give careful consideration to all sources of thermal resistance from junction to ambient. Additional heat sources mounted nearby must also be considered. For surface mount devices, heat sinking is accomplished by using the heat spreading capabilities of the PC board and its copper traces. Copper board stiffeners and plated through-holes can also be used to spread the heat generated by power devices. The following tables list thermal resistance for several different board sizes and copper areas. All measurements were taken in still air on 3/32" FR-4 board with one ounce copper. Table 1. FE Package, 16-Lead TSSOP COPPER AREA TOPSIDE* BACKSIDE VOUT 500µV/DIV 2500mm2 2500mm2 38°C/W 2 2500mm 2 2 43°C/W 2500mm 2 2 2500mm 48°C/W 2500mm2 60°C/W 225mm 2 100mm2 3028 F05 Figure 6. Noise Resulting from Tapping on a Ceramic Capacitor Thermal Considerations The power handling capability of the device will be limited by the maximum rated junction temperature (125°C). The power dissipated by the device will be made up of two components for each output: 1. Output current multiplied by the input/output voltage differential: (IOUT)(VIN – VOUT), and 2. GND pin current multiplied by the input voltage: (IGND)(VIN). The ground pin current can be found by examining the GND Pin Current curves in the Typical Performance Characteristics section. Power dissipation will be equal to the sum of the two components listed above. The LT3028 regulator has internal thermal limiting designed to protect the device during overload conditions. THERMAL RESISTANCE (JUNCTION-TO-AMBIENT) 2500mm2 1000mm 100ms/DIV BOARD AREA 2500mm 2500mm2 *Device is mounted on topside. Table 2. DHC Package, 16-Lead DFN COPPER AREA TOPSIDE* BACKSIDE BOARD AREA THERMAL RESISTANCE (JUNCTION-TO-AMBIENT) 2500mm2 2500mm2 2500mm2 40°C/W 2 2500mm 2 2500mm2 45°C/W 2500mm 2 2 50°C/W 2500mm 2 2 62°C/W 1000mm 225mm 2 100mm 2 2500mm 2500mm *Device is mounted on topside. The thermal resistance junction-to-case (θJC), measured at the Exposed Pad on the back of the die is 10°C/W for the DFN package and 8°C/W for the TSSOP package. Calculating Junction Temperature Example: Given Output 1 set for an output voltage of 3.3V, Output 2 set for an output voltage of 2.5V, an input voltage range of 3.8V to 5V, an output current range of 0mA to 500mA for Output 1, an output current range of 0mA to 100mA for Output 2 and a maximum ambient temperature of 50°C, what will the maximum junction temperature be? 3028f 13 LT3028 U W U U APPLICATIONS INFORMATION The power dissipated by each output will be equal to: IOUT(MAX)(VIN(MAX) – VOUT) + IGND(VIN(MAX)) Where for Output 1: IOUT(MAX) = 500mA VIN(MAX) = 5V IGND at (IOUT = 500mA, VIN = 5V) = 9mA For Output 2: IOUT(MAX) = 100mA VIN(MAX) = 5V IGND at (IOUT = 100mA, VIN = 5V) = 2mA So for Output 1: P = 500mA (5V – 3.3V) + 9mA (5V) = 0.90W For Output 2: P = 100mA (5V – 2.5V) + 2mA (5V) = 0.26W The thermal resistance will be in the range of 35°C/W to 55°C/W depending on the copper area. So the junction temperature rise above ambient will be approximately equal to: (0.90W + 0.26W) 50°C/W = 57.8°C The maximum junction temperature will then be equal to the maximum junction temperature rise above ambient plus the maximum ambient temperature or: TJMAX = 50°C + 57.8°C = 107.8°C Protection Features The LT3028 regulator incorporates several protection features which make it ideal for use in battery-powered circuits. In addition to the normal protection features associated with monolithic regulators, such as current limiting and thermal limiting, the device is protected against reverse input voltages and reverse voltages from output to input. The two regulators have common inputs and GND pins and are thermally coupled, however, the two outputs of the LT3028 operate independently. They can be shut down independently and a fault condition on one output will not affect the other output electrically. Current limit protection and thermal overload protection are intended to protect the device against current overload conditions at the output of the device. For normal operation, the junction temperature should not exceed 125°C. The input of the device will withstand reverse voltages of 20V. Current flow into the device will be limited to less than 1mA (typically less than 100µA) and no negative voltage will appear at the output. The device will protect both itself and the load. This provides protection against batteries which can be plugged in backward. The output of the LT3028 can be pulled below ground without damaging the device. If the input is left open circuit or grounded, the output can be pulled below ground by 20V. The output will act like an open circuit; no current will flow out of the pin. If the input is powered by a voltage source, the output will source the short-circuit current of the device and will protect itself by thermal limiting. In this case, grounding the SHDN1/SHDN2 pins will turn off the device and stop the output from sourcing the short-circuit current. The ADJ pins can be pulled above or below ground by as much as 7V without damaging the device. If the input is left open circuit or grounded, the ADJ pins will act like an open circuit when pulled below ground and like a large resistor (typically 100k) in series with a diode when pulled above ground. In situations where the ADJ pins are connected to a resistor divider that would pull the pins above their 7V clamp voltage if the output is pulled high, the ADJ pin input current must be limited to less than 5mA. For example, a resistor divider is used to provide a regulated 1.5V output from the 1.22V reference when the output is forced to 20V. The top resistor of the resistor divider must be chosen to limit the current into the ADJ pin to less than 5mA when the ADJ pin is at 7V. The 13V difference between output and ADJ pin divided by the 5mA maximum current into the ADJ pin yields a minimum top resistor value of 2.6k. 3028f 14 LT3028 U U W U APPLICATIONS INFORMATION In circuits where a backup battery is required, several different input/output conditions can occur. The output voltage may be held up while the input is either pulled to ground, pulled to some intermediate voltage or is left open circuit. When the IN pin of the LT3028 is forced below either OUT pin or either OUT pin is pulled above the IN pin, input current for the corresponding regulator will typically drop to less than 2µA. This can happen if the input of the device is connected to a discharged (low voltage) battery and the output is held up by either a backup battery or a second regulator circuit. The state of the SHDN1/SHDN2 pin will have no effect on the reverse output current when the output is pulled above the input. U PACKAGE DESCRIPTIO FE Package 16-Lead Plastic TSSOP (4.4mm) (Reference LTC DWG # 05-08-1663) Exposed Pad Variation BB 4.90 – 5.10* (.193 – .201) 3.58 (.141) 3.58 (.141) 16 1514 13 12 1110 6.60 ±0.10 9 2.94 (.116) 4.50 ±0.10 2.94 6.40 (.116) (.252) BSC SEE NOTE 4 0.45 ±0.05 1.05 ±0.10 0.65 BSC 1 2 3 4 5 6 7 8 RECOMMENDED SOLDER PAD LAYOUT 4.30 – 4.50* (.169 – .177) 0.09 – 0.20 (.0035 – .0079) 0.50 – 0.75 (.020 – .030) NOTE: 1. CONTROLLING DIMENSION: MILLIMETERS MILLIMETERS 2. DIMENSIONS ARE IN (INCHES) 3. DRAWING NOT TO SCALE 0.25 REF 1.10 (.0433) MAX 0° – 8° 0.65 (.0256) BSC 0.195 – 0.30 (.0077 – .0118) TYP 0.05 – 0.15 (.002 – .006) FE16 (BB) TSSOP 0204 4. RECOMMENDED MINIMUM PCB METAL SIZE FOR EXPOSED PAD ATTACHMENT *DIMENSIONS DO NOT INCLUDE MOLD FLASH. MOLD FLASH SHALL NOT EXCEED 0.150mm (.006") PER SIDE 3028f 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. 15 LT3028 U PACKAGE DESCRIPTIO DHC Package 16-Lead Plastic DFN (5mm × 3mm) (Reference LTC DWG # 05-08-1706) R = 0.115 TYP 5.00 ±0.10 (2 SIDES) R = 0.20 TYP 0.65 ±0.05 3.50 ±0.05 9 0.40 ± 0.10 16 3.00 ±0.10 (2 SIDES) 1.65 ±0.05 (2 SIDES) 1.65 ± 0.10 (2 SIDES) PACKAGE OUTLINE 2.20 ±0.05 PIN 1 TOP MARK (SEE NOTE 6) PIN 1 NOTCH (DHC16) DFN 1103 8 0.200 REF 0.25 ± 0.05 0.50 BSC 4.40 ±0.05 (2 SIDES) 1 0.25 ± 0.05 0.50 BSC 0.75 ±0.05 4.40 ±0.10 (2 SIDES) 0.00 – 0.05 RECOMMENDED SOLDER PAD PITCH AND DIMENSIONS NOTE: 1. DRAWING PROPOSED TO BE MADE VARIATION OF VERSION (WJED-1) IN JEDEC PACKAGE OUTLINE MO-229 2. DRAWING NOT TO SCALE 3. ALL DIMENSIONS ARE IN MILLIMETERS BOTTOM VIEW—EXPOSED PAD 4. DIMENSIONS OF EXPOSED PAD ON BOTTOM OF PACKAGE DO NOT INCLUDE MOLD FLASH. MOLD FLASH, IF PRESENT, SHALL NOT EXCEED 0.15mm ON ANY SIDE 5. EXPOSED PAD SHALL BE SOLDER PLATED 6. SHADED AREA IS ONLY A REFERENCE FOR PIN 1 LOCATION ON THE TOP AND BOTTOM OF PACKAGE RELATED PARTS PART NUMBER LT1129 DESCRIPTION 700mA, Micropower, LDO LT1175 500mA, Micropower Negative LDO LT1185 3A, Negative LDO LT1761 100mA, Low Noise Micropower, LDO LT1762 150mA, Low Noise Micropower, LDO LT1763 500mA, Low Noise Micropower, LDO LT1764/LT1764A 3A, Low Noise, Fast Transient Response, LDO LTC1844 150mA, Very Low Drop-Out LDO LT1962 300mA, Low Noise Micropower, LDO LT1963/LT1963A 1.5A, Low Noise, Fast Transient Response, LDO LT1964 200mA, Low Noise Micropower, Negative LDO LT3023 Dual 100mA, Low Noise, Micropower LDO LT3024 Dual 100mA/500mA, Low Noise, Micropower LDO COMMENTS VIN: 4.2V to 30V, VOUT(MIN) = 3.75V, IQ = 50µA, ISD < 16µA, DD, SOT-223, S8,TO220, TSSOP20 Packages Guaranteed Voltage Tolerance and Line/Load Regulation VIN: –20V to –4.3V, VOUT(MIN) = –3.8V, IQ = 45µA, ISD < 10µA, DD,SOT-223, S8 Packages Accurate Programmable Current Limit, Remote Sense VIN: –35V to –4.2V, VOUT(MIN) = –2.40V, IQ = 2.5mA, ISD < 1µA, TO220-5 Package Low Noise < 20µVRMS, Stable with 1µF Ceramic Capacitors, VIN: 1.8V to 20V, VOUT(MIN) = 1.22V, IQ = 20µA, ISD < 1µA, ThinSOT Package Low Noise < 20µVRMS, VIN: 1.8V to 20V, VOUT(MIN) = 1.22V, IQ = 25µA, ISD < 1µA, MS8 Package Low Noise < 20µVRMS, VIN: 1.8V to 20V, VOUT(MIN) = 1.22V, IQ = 30µA, ISD < 1µA, S8 Package Low Noise < 40µVRMS, "A" Version Stable with Ceramic Capacitors, VIN: 2.7V to 20V, VOUT(MIN) = 1.21V, IQ = 1mA, ISD < 1µA, DD, TO220 Packages Low Noise < 30µVRMS, Stable with 1µF Ceramic Capacitors, VIN: 1.6V to 6.5V, VOUT(MIN) = 1.25V, IQ = 40µA, ISD < 1µA, ThinSOT Package Low Noise < 20µVRMS, VIN: 1.8V to 20V, VOUT(MIN) = 1.22V, IQ = 30µA, ISD < 1µA, MS8 Package Low Noise < 40µVRMS, "A" Version Stable with Ceramic Capacitors, VIN: 2.1V to 20V, VOUT(MIN) = 1.21V, IQ = 1mA, ISD < 1µA, DD, TO220, SOT-223, S8 Packages Low Noise < 30µVRMS, Stable with Ceramic Capacitors, VIN: –0.9V to –20V, VOUT(MIN) = –1.21V, IQ = 30µA, ISD < 3µA, ThinSOT Package Low Noise < 20µVRMS, Stable with 1µF Ceramic Capacitors, VIN: 1.8V to 20V, VOUT(MIN) = 1.22V, IQ = 40µA, ISD < 1µA, MS10E, DFN Packages Low Noise < 20µVRMS, Stable with 1µF Ceramic Capacitors, VIN: 1.8V to 20V, VOUT(MIN) = 1.22V, IQ = 30µA, ISD < 1µA, DFN, TSSOP Packages 3028f 16 Linear Technology Corporation LT/TP 0904 1K • PRINTED IN USA 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com © LINEAR TECHNOLOGY CORPORATION 2004