Datasheet LT1528 (Analog Devices) - 6
| Hersteller | Analog Devices |
| Beschreibung | 3A Low Dropout Regulator for Microprocessor Applications |
| Seiten / Seite | 12 / 6 — TYPICAL PERFORMANCE CHARACTERISTICS. Ripple Rejection. Load Regulation. … |
| Dateiformat / Größe | PDF / 170 Kb |
| Dokumentensprache | Englisch |
TYPICAL PERFORMANCE CHARACTERISTICS. Ripple Rejection. Load Regulation. Transient Response. PIN FUNCTIONS. OUTPUT (Pin 1):
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LT1528
TYPICAL PERFORMANCE CHARACTERISTICS Ripple Rejection Load Regulation
80 0 VIN = VOUT(NOMINAL) + 1V 70 ΔI –5 LOAD = 1mA TO 3A 60 –10 50 COUT = 4 × 47μF SOLID TANTALUM 40 –15 COUT = 47μF 30 SOLID TANTALUM –20 RIPPLE REJECTION (dB) 20 LOAD REGULATION (mV) –25 10 IOUT = 1.5A VIN = 6V + 50mVRMS RIPPLE 0 –30 10 100 1k 10k 100k 1M –50 –25 0 25 50 75 100 125 FREQUENCY (Hz) TEMPERATURE (°C) 1528 TPC19 1528 TPC20
Transient Response Transient Response
VIN = 5V VIN = 5V 100 CIN = 3.3μF 100 CIN = 3.3μF COUT = 47μF C 50 50 OUT = 4 × 47μF 0 0 –50 –50 DEVIATION (mV) DEVIATION (mV) OUTPUT VOLTAGE OUTPUT VOLTAGE –100 –100 3 3 2 2 1 1 LOAD CURRENT (A) 0 LOAD CURRENT (A) 0 0 20 40 60 80 100 120 140 160 180 200 0 20 40 60 80 100 120 140 160 180 200 TIME (μs) TIME (μs) 1528 TPC21 1528 TPC22
PIN FUNCTIONS OUTPUT (Pin 1):
The OUTPUT pin supplies power to the normally degrade regulation, may be eliminated by con- load. A minimum output capacitor of 3.3μF is required necting the SENSE pin to the OUTPUT pin at the load as to prevent oscillations. Larger values will be needed to shown in Figure 1 (Kelvin Sense Connection). Note that achieve the transient performance required by high speed the voltage drop across the external PC traces will add microprocessors. See the Applications Information sec- to the dropout voltage of the regulator. The SENSE pin tion for more on output capacitance and reverse output bias current is 150μA at the nominal regulated output characteristics. voltage. See SENSE Pin Current vs Temperature in the Typical Performance Characteristics section. This pin is
SENSE (Pin 2):
The SENSE pin is the input to the error internally clamped to – 0.6V (one V amplifi er. Optimum regulation will be obtained at the point BE). where the SENSE pin is connected to the OUTPUT pin. For The SENSE pin can also be used with a resistor divider most applications the SENSE pin is connected directly to to achieve output voltages above 3.3V. See the Applica- the OUTPUT pin at the regulator. In critical applications tions Information section for information on adjustable small voltage drops caused by the resistance (RP) of PC operation. traces between the regulator and the load, which would 1528fb 6
TYPICAL PERFORMANCE CHARACTERISTICS Ripple Rejection Load Regulation
80 0 VIN = VOUT(NOMINAL) + 1V 70 ΔI –5 LOAD = 1mA TO 3A 60 –10 50 COUT = 4 × 47μF SOLID TANTALUM 40 –15 COUT = 47μF 30 SOLID TANTALUM –20 RIPPLE REJECTION (dB) 20 LOAD REGULATION (mV) –25 10 IOUT = 1.5A VIN = 6V + 50mVRMS RIPPLE 0 –30 10 100 1k 10k 100k 1M –50 –25 0 25 50 75 100 125 FREQUENCY (Hz) TEMPERATURE (°C) 1528 TPC19 1528 TPC20
Transient Response Transient Response
VIN = 5V VIN = 5V 100 CIN = 3.3μF 100 CIN = 3.3μF COUT = 47μF C 50 50 OUT = 4 × 47μF 0 0 –50 –50 DEVIATION (mV) DEVIATION (mV) OUTPUT VOLTAGE OUTPUT VOLTAGE –100 –100 3 3 2 2 1 1 LOAD CURRENT (A) 0 LOAD CURRENT (A) 0 0 20 40 60 80 100 120 140 160 180 200 0 20 40 60 80 100 120 140 160 180 200 TIME (μs) TIME (μs) 1528 TPC21 1528 TPC22
PIN FUNCTIONS OUTPUT (Pin 1):
The OUTPUT pin supplies power to the normally degrade regulation, may be eliminated by con- load. A minimum output capacitor of 3.3μF is required necting the SENSE pin to the OUTPUT pin at the load as to prevent oscillations. Larger values will be needed to shown in Figure 1 (Kelvin Sense Connection). Note that achieve the transient performance required by high speed the voltage drop across the external PC traces will add microprocessors. See the Applications Information sec- to the dropout voltage of the regulator. The SENSE pin tion for more on output capacitance and reverse output bias current is 150μA at the nominal regulated output characteristics. voltage. See SENSE Pin Current vs Temperature in the Typical Performance Characteristics section. This pin is
SENSE (Pin 2):
The SENSE pin is the input to the error internally clamped to – 0.6V (one V amplifi er. Optimum regulation will be obtained at the point BE). where the SENSE pin is connected to the OUTPUT pin. For The SENSE pin can also be used with a resistor divider most applications the SENSE pin is connected directly to to achieve output voltages above 3.3V. See the Applica- the OUTPUT pin at the regulator. In critical applications tions Information section for information on adjustable small voltage drops caused by the resistance (RP) of PC operation. traces between the regulator and the load, which would 1528fb 6