Datasheet LTC3852 (Analog Devices) - 9
| Manufacturer | Analog Devices |
| Description | Low Input Voltage, Synchronous Step-Down DC/DC Controller |
| Pages / Page | 32 / 9 — TYPICAL PERFORMANCE CHARACTERISTICS. Charge Pump Load Transient. Charge … |
| File Format / Size | PDF / 429 Kb |
| Document Language | English |
TYPICAL PERFORMANCE CHARACTERISTICS. Charge Pump Load Transient. Charge Pump Output Ripple. Response
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LTC3852
TYPICAL PERFORMANCE CHARACTERISTICS Charge Pump Load Transient Charge Pump Output Ripple Response
IPUMP 50mA/DIV VPUMP 20mV/DIV (AC-COUPLED) VPUMP 50mV/DIV (AC-COUPLED) 3852 G38 3852 G39 V 1μs/DIV IN1 = 3.3V V 10μs/DIV IN = 3.3V IPUMP = 25mA IPUMP = 25mA TO 50mA STEP CVPUMP = 4.7μF
Charge Pump Line Regulation with 25mA Load Effi ciency vs Supply Voltage
5.5 100 90 THEORETICAL MAX 5 80 70 60 (V) 4.5 IPUMP = 100mA 50 IPUMP = 10mA I PUMP PUMP = 1mA V 4 40 EFFICIENCY (%) 30 125°C 3.5 85°C 20 25°C 10 –45°C 3 0 1.8 2.8 3.8 4.8 2.7 3.0 3.3 3.6 3.9 4.2 4.5 VIN1 (V) SUPPLY VOLTAGE (VIN1) 3852 G41 3852 G40
PIN FUNCTIONS SENSE– (Pin 1):
The (–) Input to the Current Sense
GND2 (Pin 4):
Buck Controller Ground. All small-signal Comparators. Kelvin connect to VOUT at the current sense components and compensation components should be resistor or, if DCR sensing is used, at the inductor. Kelvin connected to this ground. The (–) terminal of CINTVCC should be closely connected to this pin. The exposed pad
SENSE+ (Pin 2):
Current Sense Comparator Noninverting must be soldered to the PCB to provide electrical contact Input. The (+) input to the current comparator is normally for the IC and for optimum thermal performance. connected to the DCR sensing network or current sensing resistor.
BG (Pin 5):
Bottom Gate Driver Output. This pin drives the gate of the bottom N-channel MOSFET between GND
PGOOD (Pin 3):
Power Good Indicator Output. Open drain and INTV logic out that is pulled to ground when the output voltage CC. exceeds the ±10% regulation window, after the internal
C+ (Pin 7):
Flying Capacitor Positive Terminal. 17μs power bad mask timer expires. 3852f 9
TYPICAL PERFORMANCE CHARACTERISTICS Charge Pump Load Transient Charge Pump Output Ripple Response
IPUMP 50mA/DIV VPUMP 20mV/DIV (AC-COUPLED) VPUMP 50mV/DIV (AC-COUPLED) 3852 G38 3852 G39 V 1μs/DIV IN1 = 3.3V V 10μs/DIV IN = 3.3V IPUMP = 25mA IPUMP = 25mA TO 50mA STEP CVPUMP = 4.7μF
Charge Pump Line Regulation with 25mA Load Effi ciency vs Supply Voltage
5.5 100 90 THEORETICAL MAX 5 80 70 60 (V) 4.5 IPUMP = 100mA 50 IPUMP = 10mA I PUMP PUMP = 1mA V 4 40 EFFICIENCY (%) 30 125°C 3.5 85°C 20 25°C 10 –45°C 3 0 1.8 2.8 3.8 4.8 2.7 3.0 3.3 3.6 3.9 4.2 4.5 VIN1 (V) SUPPLY VOLTAGE (VIN1) 3852 G41 3852 G40
PIN FUNCTIONS SENSE– (Pin 1):
The (–) Input to the Current Sense
GND2 (Pin 4):
Buck Controller Ground. All small-signal Comparators. Kelvin connect to VOUT at the current sense components and compensation components should be resistor or, if DCR sensing is used, at the inductor. Kelvin connected to this ground. The (–) terminal of CINTVCC should be closely connected to this pin. The exposed pad
SENSE+ (Pin 2):
Current Sense Comparator Noninverting must be soldered to the PCB to provide electrical contact Input. The (+) input to the current comparator is normally for the IC and for optimum thermal performance. connected to the DCR sensing network or current sensing resistor.
BG (Pin 5):
Bottom Gate Driver Output. This pin drives the gate of the bottom N-channel MOSFET between GND
PGOOD (Pin 3):
Power Good Indicator Output. Open drain and INTV logic out that is pulled to ground when the output voltage CC. exceeds the ±10% regulation window, after the internal
C+ (Pin 7):
Flying Capacitor Positive Terminal. 17μs power bad mask timer expires. 3852f 9
