LT3013B

LT3013B 250mA, 4V to 80V Low Dropout Micropower Linear Regulator with PWRGD FEATURES ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ DESCRIPTIO Wide Input Voltage Range: 4V to 80V Low Quiescent Current: 65µA Low Dropout Voltage: 400mV Output Current: 250mA No Protection Diodes Needed Adjustable Output from 1.24V to 60V Stable with 3.3µF Output Capacitor Stable with Aluminum, Tantalum or Ceramic Capacitors Reverse-Battery Protection No Reverse Current Flow from Output to Input Thermal Limiting Thermally Enhanced 16-Lead TSSOP and 12 Pin (4mm × 3mm) DFN Package The LT®3013B is a high voltage, micropower low dropout linear regulator. The device is capable of supplying 250mA of output current with a dropout voltage of 400mV. Designed for use in battery-powered or high voltage systems, the low quiescent current (65µA operating) makes the LT3013B an ideal choice. Quiescent current is also well controlled in dropout. Other features of the LT3013B include a PWRGD flag to indicate output regulation. The delay between regulated output level and flag indication is programmable with a single capacitor. The LT3013B also has the ability to operate with very small output capacitors. The regulator is stable with only 3.3µF on the output while most older devices require between 10µF and 100µF for stability. Small ceramic capacitors can be used without any need for series resistance (ESR) as is common with other regulators. Internal protection circuitry includes reverse-battery protection, current limiting, thermal limiting and reverse current protection. The device is available with an adjustable output with a 1.24V reference voltage. The LT3013B regulator is available in the thermally enhanced 16-lead TSSOP and the low profile (0.75mm), 12 pin (4mm × 3mm) DFN package, both providing excellent thermal characteristics. , LT, LTC and LTM are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. APPLICATIO S ■ ■ ■ ■ Low Current High Voltage Regulators Regulator for Battery-Powered Systems Telecom Applications Automotive Applications TYPICAL APPLICATIO IN VIN 5.4V TO 80V 1µF 1.6M PWRGD GND ADJ CT OUT LT3013B 400 5V Supply DROPOUT VOLTAGE (mV) VOUT 5V 250mA 3.3µF 350 300 250 200 150 100 50 0 0 50 100 150 200 OUTPUT CURRENT (mA) 250 3013 TA02 750k 249k 3013 TA01 1000pF U Dropout Voltage 3013bfa U U 1 LT3013B ABSOLUTE (Note 1) AXI U RATI GS Storage Temperature Range TSSOP Package ........................... –65°C to 150°C DFN Package ............................... –65°C to 125°C Operating Junction Temperature Range (Notes 3, 9, 10) ........................... –40°C to 125°C Lead Temperature (FE16 Soldering, 10 sec) ... 300°C IN Pin Voltage ................................................... ±80V OUT Pin Voltage ............................................... ±60V IN to OUT Differential Voltage ........................... ± 80V ADJ Pin Voltage .................................................. ± 7V CT Pin Voltage ........................................... 7V, –0.5V PWRGD Pin Voltage ................................ 80V, –0.5V Output Short-Circuit Duration ..................... Indefinite PACKAGE/ORDER I FOR ATIO TOP VIEW NC OUT OUT ADJ GND PWRGD 1 2 3 13 4 5 6 9 8 7 NC NC CT 12 NC 11 IN 10 IN DE PACKAGE 12-LEAD (4mm × 3mm) PLASTIC DFN TJMAX = 125°C, θJA = 40°C/ W, θJC = 16°C/ W EXPOSED PAD (PIN13) IS GND MUST BE SOLDERED TO PCB ORDER PART NUMBER LT3013BEDE DE PART MARKING 3013B Order Options Tape and Reel: Add #TR Lead Free: Add #PBF Lead Free Tape and Reel: Add #TRPBF Lead Free Part Marking: http://www.linear.com/leadfree/ Consult LTC Marketing for parts specified with wider operating temperature ranges. ELECTRICAL CHARACTERISTICS The ● denotes specifications which apply over the full operating temperature range, otherwise specifications are at TJ = 25°C. PARAMETER Minimum Input Voltage ADJ Pin Voltage (Notes 2,3) Line Regulation Load Regulation (Note 2) CONDITIONS ILOAD = 250mA VIN = 4V, ILOAD = 1mA 4.5V < VIN < 80V, 1mA < ILOAD < 250mA ∆VIN = 4V to 80V, ILOAD = 1mA (Note 2) VIN = 4.5V, ∆ILOAD = 1mA to 250mA VIN = 4.5V, ∆ILOAD = 1mA to 250mA ● ● ● ● 2 U U W WW U W TOP VIEW GND NC OUT OUT ADJ GND PWRGD GND 1 2 3 4 5 6 7 8 17 16 GND 15 NC 14 IN 13 IN 12 NC 11 NC 10 CT 9 GND FE PACKAGE 16-LEAD PLASTIC TSSOP TJMAX = 125°C, θJA = 40°C/ W, θJC = 16°C/ W EXPOSED PAD (PIN17) IS GND MUST BE SOLDERED TO PCB ORDER PART NUMBER LT3013BEFE FE PART MARKING 3013BEFE MIN 1.225 1.2 TYP 4 1.24 1.24 0.1 7 MAX 4.5 1.255 1.28 5 12 25 UNITS V V V mV mV mV 3013bfa LT3013B ELECTRICAL CHARACTERISTICS The ● denotes specifications which apply over the full operating temperature range, otherwise specifications are at TJ = 25°C. PARAMETER Dropout Voltage VIN = VOUT(NOMINAL) (Notes 4, 5) CONDITIONS ILOAD = 10mA ILOAD = 10mA ILOAD = 50mA ILOAD = 50mA ILOAD = 250mA ILOAD = 250mA GND Pin Current VIN = 4.5V (Notes 4, 6) Output Voltage Noise ADJ Pin Bias Current PWRGD Trip Point PWRGD Trip Point Hysteresis PWRGD Output Low Voltage CT Pin Charging Current CT Pin Voltage Differential Ripple Rejection Current Limit Reverse Output Current (Note 8) VCT(PWRGD High) – VCT(PWRGD Low) VIN = 7V(Avg), VRIPPLE = 0.5VP-P, fRIPPLE = 120Hz, ILOAD = 250mA VIN = 7V, VOUT = 0V VIN = 4.5V, ∆VOUT = – 0.1V (Note 2) VOUT = 1.24V, VIN < 1.24V (Note 2) ● 65 270 12 25 ILOAD = 0mA ILOAD = 100mA ILOAD = 250mA COUT = 10µF, ILOAD = 250mA, BW = 10Hz to 100kHz (Note 7) % of Nominal Output Voltage, Output Rising % of Nominal Output Voltage IPWRGD = 50µA ● ● ● MIN TYP 160 250 MAX 230 300 340 420 490 620 120 18 100 94 250 6 UNITS mV mV mV mV mV mV µA mA mA µVRMS nA % % mV µA V dB mA mA µA ● 400 ● ● ● 65 3 10 100 30 85 90 1.1 140 3.6 1.6 75 400 Note 1: Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. Exposure to any Absolute Maximum Rating condition for extended periods may affect device reliability and lifetime. Note 2: The LT3013B is tested and specified for these conditions with the ADJ pin connected to the OUT pin. Note 3: 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 4: To satisfy requirements for minimum input voltage, the LT3013B is tested and specified for these conditions with an external resistor divider (249k bottom, 549k top) for an output voltage of 4V. The external resistor divider will add a 5µA DC load on the output. Note 5: 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 6: GND pin current is tested with VIN = 4.5V and a current source load. This means the device is tested while operating close to its dropout region. This is the worst-case GND pin current. The GND pin current will decrease slightly at higher input voltages. Note 7: ADJ pin bias current flows into the ADJ pin. Note 8: Reverse output current is tested with the IN pin grounded and the OUT pin forced to the rated output voltage. This current flows into the OUT pin and out the GND pin. Note 9: The LT3013BE is guaranteed to meet performance specifications from 0°C to 125°C operating junction temperature. Specifications over the –40°C to 125°C operating junction temperature range are assured by design, characterization and correlation with statistical process controls. 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. 3013bfa 3 LT3013B TYPICAL PERFOR A CE CHARACTERISTICS Typical Dropout Voltage 600 500 TJ = 125°C GUARANTEED DROPOUT VOLTAGE (mV) DROPOUT VOLTAGE (mV) DROPOUT VOLTAGE (mV) 400 300 200 100 0 TJ = 25°C 0 50 100 150 200 OUTPUT CURRENT (mA) 600 500 Quiescent Current 1.260 1.255 DROPOUT VOLTAGE (mV) 400 300 IL = 100mA ADJ PIN VOLTAGE (V) IL = 250mA 1.250 1.245 1.240 1.235 1.230 1.225 QUIESCENT CURRENT (µA) IL = 50mA 200 IL = 10mA 100 0 –50 IL = 1mA –25 50 25 0 75 TEMPERATURE (°C) GND Pin Current 1.2 1.0 TJ = 25°C *FOR VOUT = 1.24V 10 9 8 GND PIN CURRENT (mA) GND PIN CURRENT (mA) 0.8 0.6 0.4 0.2 0 7 6 5 4 3 2 1 GND PIN CURRENT (mA) RL = 49.6Ω IL = 25mA* RL = 124Ω IL = 10mA* RL = 1.24k IL = 1mA* 0 1 2 34567 INPUT VOLTAGE (V) 4 UW 3013 G01 Guaranteed Dropout Voltage 600 500 400 300 200 100 0 0 50 150 100 200 OUTPUT CURRENT (mA) 250 3013 G02 Dropout Voltage 600 500 400 300 IL = 50mA 200 IL = 10mA 100 0 –50 –25 IL = 1mA 50 25 0 75 TEMPERATURE (°C) 100 125 IL = 250mA IL = 100mA = TEST POINTS TJ ≤ 125°C TJ ≤ 25°C 250 3013 G03 ADJ Pin Voltage IL = 1mA 80 70 60 50 40 30 20 10 0 50 75 25 TEMPERATURE (°C) 100 125 0 Quiescent Current TJ = 25°C RL = ∞ 100 125 1.220 – 50 – 25 0 1 2 34567 INPUT VOLTAGE (V) 8 9 10 3013 G03 3013 G05 3013 G06 GND Pin Current TJ = 25°C, *FOR VOUT = 1.24V 10 GND Pin Current vs ILOAD VIN = 4.5V 9 TJ = 25°C 8 7 6 5 4 3 2 RL = 4.96Ω IL = 250mA* RL = 12.4Ω IL = 100mA* RL = 24.8Ω, IL = 50mA* 0 1 2 34567 INPUT VOLTAGE (V) 8 9 10 1 0 0 50 100 150 200 LOAD CURRENT (mA) 250 3013 G09 8 9 10 0 3013 G07 3013 G08 3013bfa LT3013B TYPICAL PERFOR A CE CHARACTERISTICS ADJ Pin Bias Current PWRGD TRIP POINT (% OF OUTPUT VOLTAGE) 50 45 95 94 93 92 91 90 89 88 87 86 85 – 50 – 25 0 50 75 25 TEMPERATURE (°C) 100 125 OUTPUT FALLING OUTPUT RISING PWRGD OUTPUT LOW VOLTAGE (mV) ADJ PIN BIAS CURRENT (nA) 40 35 30 25 20 15 10 5 0 – 50 – 25 0 50 75 25 TEMPERATURE (°C) 100 125 CT Charging Current 4.0 3.5 PWRGD TRIPPED HIGH 2.0 CT COMPARATOR THRESHOLDS (V) CT CHARGING CURRENT (µA) 3.0 2.5 2.0 1.5 1.0 0.5 0 – 50 – 25 0 50 75 25 TEMPERATURE (°C) 100 125 1.2 1.0 0.8 0.6 0.4 0.2 0 – 50 – 25 0 VCT (LOW) 50 75 25 TEMPERATURE (°C) 100 125 CURRENT LIMIT (A) Current Limit 0.7 REVERSE OUTPUT CURRENT (µA) CURRENT LIMIT (A) 0.5 0.4 0.3 0.2 0.1 VIN = 7V VOUT = 0V 50 25 0 75 TEMPERATURE (°C) 100 125 REVERSE OUTPUT CURRENT (µA) 0.6 0 –50 –25 UW 3013 G13 3013 G27 3013 G15 PWRGD Trip Point 200 180 160 140 120 100 80 60 40 20 PWRGD Output Low Voltage IPWRGD = 50µA 0 – 50 – 25 0 50 75 25 TEMPERATURE (°C) 100 125 3013 G25 3013 G26 CT Comparator Thresholds 1.0 VCT (HIGH) 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0 1.8 1.6 1.4 Current Limit VOUT = 0V TJ = 25°C TJ = 125°C 0 10 20 30 40 50 60 INPUT VOLTAGE (V) 70 80 3013 G28 3013 G14 Reverse Output Current 200 TJ = 25°C 180 VIN = 0V VOUT = VADJ 160 140 120 100 80 60 40 20 0 0 1 2 345678 OUTPUT VOLTAGE (V) 9 10 CURRENT FLOWS INTO OUTPUT PIN ADJ PIN CLAMP (SEE APPLICATIONS INFORMATION) 35 30 25 20 15 10 5 Reverse Output Current VIN = 0V VOUT = VADJ = 1.24V 0 – 50 – 25 0 75 50 25 TEMPERATURE (°C) 100 125 3013 G16 3013 G17 3013bfa 5 LT3013B TYPICAL PERFOR A CE CHARACTERISTICS Input Ripple Rejection 92 88 RIPPLE REJECTION (dB) 80 84 80 76 72 68 64 VIN = 4.5V + 0.5VP-P RIPPLE AT f = 120Hz IL = 250mA VOUT = 1.24V 50 25 0 75 TEMPERATURE (°C) 100 125 RIPPLE REJECTION (dB) MINIMUM INPUT VOLTAGE (V) 60 –50 –25 Load Regulation –2 LOAD REGULATION (mV) OUTPUT NOISE SPECTRAL DENSITY (µV/√Hz) 0 ∆IL = 1mA TO 250mA –4 –6 –8 –10 –12 –14 –16 –18 –20 – 50 – 25 0 75 50 25 TEMPERATURE (°C) 100 125 10Hz to 100kHz Output Noise 0.15 OUTPUT VOLTAGE DEVIATION (V) VOUT 100µV/DIV LOAD CURRENT (mA) COUT = 10µF IL = 250mA VOUT = VADJ 6 UW 3013 G18 Input Ripple Rejection 100 VIN = 4.5V + 50mVRMS RIPPLE 90 ILOAD = 250mA 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5 Minimum Input Voltage ILOAD = 250mA 70 60 50 40 30 20 10 0 10 100 1k 10k FREQUENCY (Hz) 100k 1M 3013 G19 COUT = 10µF COUT = 3.3µF 0 – 50 – 25 0 50 75 25 TEMPERATURE (°C) 100 125 3013 G20 Output Noise Spectral Density 10 COUT = 3.3µF ILOAD = 250mA 1 0.1 0.01 10 100 1k 10k FREQUENCY (Hz) 100k 3013 G22 3013 G21 Transient Response 0.10 0.05 0 –0.05 –0.10 –0.15 300 200 100 0 0 100 300 200 TIME (µs) 400 500 3013 G24 VIN = 6V VOUT = 5V CIN = 3.3µF CERAMIC COUT = 3.3µF CERAMIC ∆ILOAD = 100mA TO 200mA 1ms/DIV 3013B G23 3013bfa LT3013B PI FU CTIO S OUT (Pins 2, 3)/(Pins 3, 4): Output. The output supplies power to the load. A minimum output capacitor of 3.3µF is required to prevent oscillations. 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. ADJ (Pin 4)/(Pin 5): Adjust. This is the input to the error amplifier. This pin is internally clamped to ±7V. It has a bias current of 30nA which flows into the pin (see curve of ADJ Pin Bias Current vs Temperature in the Typical Performance Characteristics). The ADJ pin voltage is 1.24V referenced to ground, and the output voltage range is 1.24V to 60V. GND (Pins 5, 13)/(Pins 1, 6, 8, 9, 16, 17): Ground. The exposed backside of the package is an electrical connection for GND. As such, to ensure optimum device operation and thermal performance, the exposed pad must be connected directly to pin 5/pin 6 on the PC board. PWRGD (Pin 6)/(Pin 7): Power Good. The PWRGD flag is an open collector flag to indicate that the output voltage has come up to above 90% of the nominal output voltage. There is no internal pull-up on this pin; a pull-up resistor must be used. The PWRGD pin will change state from an open-collector to high impedance after both the output is above 90% of the nominal voltage and the capacitor on the CT pin has charged through a 1V differential. The maximum pull-down current of the PWRGD pin in the low state is 50µA. U U U (DFN Package)/(TSSOP Package) CT (Pin 7)/(Pin 10): Timing Capacitor. The CT pin allows the use of a small capacitor to delay the timing between the point where the output crosses the PWRGD threshold and the PWRGD flag changes to a high impedance state. Current out of this pin during the charging phase is 3µA. The voltage difference between the PWRGD low and PWRGD high states is 1.6V (see the Applications Information Section). IN (Pins 10, 11)/(Pins 13,14): Input. Power is supplied to the device through the IN pin. A bypass capacitor is required on this pin 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 batterypowered circuits. A bypass capacitor in the range of 1µF to 10µF is sufficient. The LT3013B is designed to withstand reverse voltages on the IN pin with respect to ground and the OUT pin. In the case of a reversed input, which can happen if a battery is plugged in backwards, the LT3013B will act as if there is a diode in series with its input. There will be no reverse current flow into the LT3013B and no reverse voltage will appear at the load. The device will protect both itself and the load. NC (Pins 1, 8, 9, 12)/(Pins 2, 11, 12, 15): No Connect. No Connect pins may be floated, tied to IN or tied to GND. 3013bfa 7 LT3013B APPLICATIO S I FOR ATIO The LT3013B is a 250mA high voltage low dropout regulator with micropower quiescent current. The device is capable of supplying 250mA at a dropout voltage of 400mV. Operating quiescent current is only 65µA. In addition to the low quiescent current, the LT3013B incorporates several protection features which make it ideal for use in battery-powered systems. The device is protected against both reverse input and reverse output voltages. In battery backup applications where the output can be held up by a backup battery when the input is pulled to ground, the LT3013B acts like it has a diode in series with its output and prevents reverse current flow. Adjustable Operation The LT3013B has an output voltage range of 1.24V to 60V. 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 voltage at the adjust pin at 1.24V referenced to ground. The current in R1 is then equal to 1.24V/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 less than 250k to minimize errors in the output voltage caused by the ADJ pin bias current. The adjustable device is tested and specified with the ADJ pin tied to the OUT pin and a 5µA DC load (unless otherwise specified) for an output voltage of 1.24V. Specifications Figure 1. Adjustable Operation 8 U for output voltages greater than 1.24V will be proportional to the ratio of the desired output voltage to 1.24V; (VOUT/ 1.24V). For example, load regulation for an output current change of 1mA to 250mA is –7mV typical at VOUT = 1.24V. At VOUT = 12V, load regulation is: (12V/1.24V) • (–7mV) = –68mV Output Capacitance and Transient Response The LT3013B 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 3.3µF with an ESR of 3Ω or less is recommended to prevent oscillations. The LT3013B 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 LT3013B, will increase the effective output capacitor value. 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 specified with EIA temperature characteristic codes of Z5U, Y5V, X5R and X7R. The Z5U and Y5V dielectrics are good for providing high capacitances in a small package, but they tend to have strong voltage and IN VIN OUT R2 R1 LT3013B ADJ GND 3013 F01 W UU + VOUT VOUT = 1.24V 1 + R2 + (IADJ)(R2) R1 VADJ = 1.24V IADJ = 30nA AT 25°C OUTPUT RANGE = 1.24V TO 60V () 3013bfa LT3013B APPLICATIO S I FOR ATIO temperature coefficients as shown in Figures 2 and 3. When used with a 5V regulator, a 16V 10µF Y5V capacitor can exhibit an effective value as low as 1µF to 2µF for the DC bias voltage applied and 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. Care still must be exercised when using X5R and X7R capacitors; the X5R and X7R 20 0 CHANGE IN VALUE (%) BOTH CAPACITORS ARE 16V, 1210 CASE SIZE, 10µF X5R –20 –40 –60 Y5V –80 –100 0 2 4 8 6 10 12 DC BIAS VOLTAGE (V) 14 16 3013 F02 Figure 2. Ceramic Capacitor DC Bias Characterics 40 20 CHANGE IN VALUE (%) 0 X5R –20 –40 –60 –80 Y5V BOTH CAPACITORS ARE 16V, 1210 CASE SIZE, 10µF –100 50 25 75 –50 –25 0 TEMPERATURE (°C) 100 125 3013 F03 Figure 3. Ceramic Capacitor Temperature Characterics U codes only specify operating temperature range and maximum capacitance change over temperature. Capacitance change due to DC bias with X5R and X7R capacitors is better than Y5V and Z5U capacitors, but can still be significant enough to drop capacitor values below appropriate levels. Capacitor DC bias characteristics tend to improve as component case size increases, but expected capacitance at operating voltage should be verified. 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. PWRGD Flag and Timing Capacitor Delay The PWRGD flag is used to indicate that the ADJ pin voltage is within 10% of the regulated voltage. The PWRGD pin is an open-collector output, capable of sinking 50µA of current when the ADJ pin voltage is low. There is no internal pull-up on the PWRGD pin; an external pull-up resistor must be used. When the ADJ pin rises to within 10% of its final reference value, a delay timer is started. At the end of this delay, programmed by the value of the capacitor on the CT pin, the PWRGD pin switches to a high impedance and is pulled up to a logic level by an external pull-up resistor. To calculate the capacitor value on the CT pin, use the following formula: C TIME = ICT • tDELAY VCT (HIGH) – VCT (LOW) W UU Figure 4 shows a block diagram of the PWRGD circuit. At startup, the timing capacitor is discharged and the PWRGD pin will be held low. As the output voltage increases and the ADJ pin crosses the 90% threshold, the JK flip-flop is reset, and the 3µA current source begins to charge the 3013bfa 9 LT3013B APPLICATIO S I FOR ATIO ADJ + J Q VCT(HIGH) – VBE (~1.1V) VREF • 90% – Figure 4. PWRGD Circuit Block Diagram timing capacitor. Once the voltage on the CT pin reaches the VCT(HIGH) threshold (approximately 1.7V at 25°C), the capacitor voltage is clamped and the PWRGD pin is set to a high impedance state. During normal operation, an internal glitch filter will ignore short transients (