Datasheet ADP1870, ADP1871 (Analog Devices) - 4

FabricanteAnalog Devices
DescripciónSynchronous Buck Controller with Constant On-Time and Valley Current Mode
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ADP1870/ADP1871. Data Sheet. Parameter. Symbol. Conditions. Min. Typ. Max. Unit

ADP1870/ADP1871 Data Sheet Parameter Symbol Conditions Min Typ Max Unit

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ADP1870/ADP1871 Data Sheet Parameter Symbol Conditions Min Typ Max Unit
ADP1870ARMZ-0.6/ 600 kHz ADP1871ARMZ-0.6 (600 kHz) On-Time VIN = 5 V, VOUT = 2 V, TJ = 25°C 500 540 580 ns Minimum On-Time VIN = 20 V, VOUT = 0.8 V 82 110 ns Minimum Off-Time 65% duty cycle (maximum) 340 400 ns ADP1870ARMZ-1.0/ 1.0 MHz ADP1871ARMZ-1.0 (1.0 MHz) On-Time VIN = 5 V, VOUT = 2 V, TJ = 25°C 285 312 340 ns Minimum On-Time VIN = 20 V 60 85 ns Minimum Off-Time 45% duty cycle (maximum) 340 400 ns OUTPUT DRIVER CHARACTERISTICS High-Side Driver Output Source Resistance ISOURCE = 1.5 A, 100 ns, positive pulse (0 V to 5 V) 2.25 3 Ω Output Sink Resistance ISINK = 1.5 A, 100 ns, negative pulse (5 V to 0 V) 0.7 1 Ω Rise Time2 tr,DRVH VBST − VSW = 4.4 V, CIN = 4.3 nF (see Figure 60) 25 ns Fall Time2 tf,DRVH VBST − VSW = 4.4 V, CIN = 4.3 nF (see Figure 61) 11 ns Low-Side Driver Output Source Resistance ISOURCE = 1.5 A, 100 ns, positive pulse (0 V to 5 V) 1.6 2.2 Ω Output Sink Resistance ISINK = 1.5 A, 100 ns, negative pulse (5 V to 0 V) 0.7 1 Ω Rise Time2 tr,DRVL VREG = 5.0 V, CIN = 4.3 nF (see Figure 61) 18 ns Fall Time2 tf,DRVL VREG = 5.0 V, CIN = 4.3 nF (see Figure 60) 16 ns Propagation Delays DRVL Fall to DRVH Rise2 ttpdhDRVH VBST − VSW = 4.4 V (see Figure 60) 15.4 ns DRVH Fall to DRVL Rise2 ttpdhDRVL VBST − VSW = 4.4 V (see Figure 61) 18 ns SW Leakage Current ISWLEAK VBST = 25 V, VSW = 20 V, VREG = 5 V 110 µA Integrated Rectifier Channel Impedance ISINK = 10 mA 22 Ω PRECISION ENABLE THRESHOLD Logic High Level VIN = 2.9 V to 20 V, VREG = 2.75 V to 5.5 V 245 285 330 mV Enable Hysteresis VIN = 2.9 V to 20 V, VREG = 2.75 V to 5.5 V 37 mV COMP VOLTAGE COMP Clamp Low Voltage VCOMP(low) From disabled state, release COMP/EN pin to enable 0.47 V device (2.75 V ≤ VREG ≤ 5.5 V) COMP Clamp High Voltage VCOMP(high) (2.75 V ≤ VREG ≤ 5.5 V) 2.55 V COMP Zero Current Threshold VCOMP_ZCT (2.75 V ≤ VREG ≤ 5.5 V) 1.07 V THERMAL SHUTDOWN TTMSD Thermal Shutdown Threshold Rising temperature 155 °C Thermal Shutdown Hysteresis 15 °C Hiccup Current Limit Timing 6 ms 1 The maximum specified values are with the closed loop measured at 10% to 90% time points (see Figure 60 and Figure 61), CGATE = 4.3 nF, and the upper- and lower-side MOSFETs being Infineon BSC042N03MSG. 2 Not automatic test equipment (ATE) tested. Rev. B | Page 4 of 44 Document Outline Features Applications General Description Typical Applications Circuit Revision History Specifications Absolute Maximum Ratings Thermal Resistance Boundary Condition ESD Caution Pin Configuration and Function Descriptions Typical Performance Characteristics ADP1870/ADP1871 Block Diagram Theory of Operation Startup Soft Start Precision Enable Circuitry Undervoltage Lockout On-Board Low Dropout Regulator Thermal Shutdown Programming Resistor (RES) Detect Circuit Valley Current-Limit Setting Hiccup Mode During Short Circuit Synchronous Rectifier Power Saving Mode (PSM) Version (ADP1871) Timer Operation Pseudo-Fixed Frequency Applications Information Feedback Resistor Divider Inductor Selection Output Ripple Voltage (ΔVRR) Output Capacitor Selection Compensation Network Output Filter Impedance (ZFILT) Error Amplifier Output Impedance (ZCOMP) Error Amplifier Gain (GM) Current-Sense Loop Gain (GCS) Crossover Frequency Efficiency Considerations Channel Conduction Loss MOSFET Driver Loss Switching Loss Diode Conduction Loss Inductor Loss Input Capacitor Selection Thermal Considerations Design Example Input Capacitor Inductor Current Limit Programming Output Capacitor Feedback Resistor Network Setup Compensation Network Loss Calculations External Component Recommendations Layout Considerations IC Section (Left Side of Evaluation Board) Power Section Differential Sensing Typical Applications Circuits 15 A, 300 kHz High Current Application Circuit 5.5 V Input, 600 kHz Application Circuit 300 kHz High Current Application Circuit Outline Dimensions Ordering Guide