Datasheet LTC3670 (Analog Devices) - 3

LTC3670
ELECTRICAL CHARACTERISTICS The
l
denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. VIN = 3.6V, unless otherwise noted. SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS Synchronous Buck Regulator
fOSC Oscillator Frequency 1.91 2.25 2.59 MHz VBUCKFB Buck Regulated Feedback Voltage l 0.78 0.8 0.82 V IBUCKFB Feedback Pin Input Bias Current l ±20 nA IMAXP PMOS Switch Maximum Peak Current (Note 6) 600 800 1100 mA RP(BUCK) PMOS Switch On-Resistance 0.6 Ω RN(BUCK) NMOS Switch On-Resistance 0.7 Ω RPD(BUCK) SW Pin Pull-Down Resistance in Shutdown 10 kΩ tSS(BUCK) Soft-Start Time 0.6 ms
Each LDO Regulator
VLDO LDO Regulated Feedback Voltage LDO Output, ILDO = 1mA to 150mA l 0.78 0.8 0.82 V LDO Line Regulation (Note 7) ILDO = 1mA, VIN = 2.5V to 5.5V 0.25 mV/V LDO Load Regulation (Note 7) ILDO = 1mA to 150mA –5 µV/mA ILDO_FB Feedback Pin Input Bias Current l ±20 nA Short-Circuit Output Current (Note 6) 420 mA VDROP Dropout Voltage (Note 8) ILDO = 150mA VIN = 3.6V 150 200 mV VIN = 2.5V 200 300 mV tSS(LDO) Soft-Start Time 0.1 ms RPD(LDO) Output Pull-Down Resistance in Shutdown 10 kΩ
Note 1:
Stresses beyond those listed under Absolute Maximum Ratings
Note 5:
PGOOD threshold is expressed as a percentage of the feedback may cause permanent damage to the device. Exposure to any Absolute regulation voltage. The threshold is measured for the feedback pin voltage Maximum Rating condition for extended periods may affect device rising. reliability and lifetime.
Note 6:
The current limit features are intended to protect the IC from
Note 2:
This IC includes overtemperature protection that is intended short term or intermittent fault conditions. Prolonged operation above to protect the device during momentary overload conditions. Junction the specified Absolute Maximum pin current rating may result in device temperatures will exceed 125°C when overtemperature protection is degradation or failure. active. Continuous operation above the specified maximum operating
Note 7:
Measured with the LDO running unity gain, with output tied to junction temperature may result in device degradation or failure. feedback pin.
Note 3:
The LTC3670 is guaranteed to meet performance specifications
Note 8:
Dropout voltage is the minimum input to output voltage differential from 0°C to 85°C. Specifications over the –40°C to 85°C operating needed for an LDO to maintain regulation at a specified output current. temperature range are assured by design, characterization and correlation When an LDO is in dropout, its output voltage will be equal to: with statistical process controls. VIN – VDROP
Note 4:
Dynamic supply current is higher due to the gate charge delivered to the buck regulator’s internal MOSFET switches at the switching frequency. Rev A For more information www.analog.com 3 Document Outline Features Description Applications Typical Application Absolute Maximum Ratings Pin Configuration Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Typical Application Related Parts