Datasheet LTC3839 (Analog Devices) - 3
| Manufacturer | Analog Devices |
| Description | Fast, Accurate, 2-Phase, Single-Output Step-Down DC/DC Controller with Differential Output Sensing |
| Pages / Page | 50 / 3 — ELECTRICAL CHARACTERISTICS. The. denotes the specifications which apply … |
| File Format / Size | PDF / 944 Kb |
| Document Language | English |
ELECTRICAL CHARACTERISTICS. The. denotes the specifications which apply over the specified operating
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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
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
