Datasheet LTC3839 (Analog Devices) - 3

LTC3839
ELECTRICAL CHARACTERISTICS The
l
denotes the specifications which apply over the specified operating junction temperature range, otherwise specifications are at TA = 25°C. VIN = 15V unless otherwise noted (Note 3). SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS Main Control Loops
VIN Input Voltage Operating Range 4.5 38 V VOUT(REG) Regulated Output Voltage Operating Range VOUT Regulated Differentially with Respect to 0.6 5.5 V V – OUTSENSE IQ Input DC Supply Current RUN Enabled MODE/PLLIN = 0V, No Load 3 mA Shutdown Supply Current RUN = 0V 15 µA VOUTSENSE(REG) Regulated Differential Feedback Voltage ITH1 = 1.2V (Note 5) (V + – OUTSENSE – VOUTSENSE ) TA = 25°C 0.5985 0.6 0.6015 V TA = 0°C to 85°C l 0.596 0.6 0.604 V TA = –40°C to 125°C l 0.594 0.6 0.606 V Regulated Differential Feedback Voltage VIN = 4.5V to 38V, ITH1 = 0.5V to 1.9V l 0.591 0.6 0.609 V Over Line, Load and Common Mode –0.5V < V – OUTSENSE < 0.5V (Notes 5, 7) I + + + – VOUTSENSE VOUTSENSE Input Bias Current VOUTSENSE – VOUTSENSE = 0.6V ±5 ±25 nA I – – + – VOUTSENSE VOUTSENSE Input Bias Current VOUTSENSE – VOUTSENSE = 0.6V –25 –50 µA gm(EA) Error Amplifier Transconductance ITH = 1.2V (Note 5) 1.7 mS tON(MIN)1,2 Minimum Top Gate On-Time VIN = 38V, VOUT = 0.6V, RT = 20k (Note 6) 30 ns tOFF(MIN)1,2 Minimum Top Gate Off-Time (Note 6) 90 ns
Current Sensing
V – SENSE(MAX)1,2 Maximum Valley Current Sense Threshold VRNG = 2V, VFB = 0.57V, VSENSE = 2.5V l 80 100 120 mV (V + – – SENSE1,2 – VSENSE1,2 ) VRNG = 0V, VFB = 0.57V, VSENSE = 2.5V l 21 30 40 mV V – RNG = INTVCC, VFB = 0.57V, VSENSE = 2.5V l 39 50 61 mV V – SENSE(MIN)1,2 Minimum Valley Current Sense Threshold VRNG = 2V, VFB = 0.63V, VSENSE = 2.5V –50 mV (V + – – SENSE1,2 – VSENSE1,2 ) VRNG = 0V, VFB = 0.63V, VSENSE = 2.5V –15 mV (Forced Continuous Mode) V – RNG = INTVCC, VFB = 0.63V, VSENSE = 2.5V –25 mV I + + SENSE1,2 SENSE1,2+ Pins Input Bias Current VSENSE = 0.6V ±5 ±50 nA V + SENSE = 5V 1 ±2 µA I – – SENSE1,2 SENSE1,2– Pins Input Bias Current VSENSE = 0.6V 1.2 µA (Internal 500k Resistor to SGND) V – SENSE = 5V 10 µA
Start-Up and Shutdown
VRUN RUN Pin On Threshold VRUN Rising l 1.1 1.2 1.3 V RUN Pin On Hysteresis VRUN Falling from On Threshold 100 mV IRUN RUN Pin Pull-Up Current when Off RUN = SGND 2.5 µA RUN Pin Pull-Up Current Hysteresis 10 µA (IRUN(ON) – IRUN(OFF)) UVLO INTVCC Undervoltage Lockout INTVCC Falling l 3.3 3.7 V INTVCC Rising l 4.2 4.5 V ITRACK/SS Soft-Start Pull-Up Current 0V < TRACK/SS < 0.6V 1 µA
Frequency and Clock Synchronization
f Clock Output Frequency RT = 205k 200 kHz (Steady-State Switching Frequency) RT = 80.6k 450 500 550 kHz RT = 18.2k 2000 kHz Channel 2 Phase (Relative to Channel 1) PHASMD = SGND 180 Deg PHASMD = Floating 180 Deg PHASMD = INTVCC 240 Deg CLKOUT Phase (Relative to Channel 1) PHASMD = SGND 60 Deg PHASMD = Floating 90 Deg PHASMD = INTVCC 120 Deg VPLLIN(H) Clock Input High Level Into MODE/PLLIN 2 V 3839fa 3 Document Outline Features Applications Description Typical Application Absolute Maximum Ratings Pin Configuration Order Information Typical Performance Characteristics Pin Functions Functional Diagram Operation Typical Applications Typical Application Related Parts