PDF《19-6903; Rev 1; 6/14》

TA = TJ = -40°C to +125°C, unless otherwise noted. Typical values are at TA = +25°C. All voltages are referenced to GND, unless otherwise noted) (Note 2) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS INPUT SUPPLY (IN) Input Voltage Range VIN

4 60 V Input Shutdown Current IIN-SH VEN/UVLO = 0V, TA = +25°C 0.67 1.2 2.25 ?A Input Supply Current IQ-PFM VMODE = unconnected (Note 2)

18 32 IQ-PWM Normal switching mode, VIN = 24V

245 525

760 EXTERNAL BIAS (VOUT) VOUT Switchover Threshold 2.96 3.05 3.12 V ENABLE/UVLO (EN/UVLO) EN/UVLO Threshold VENR VEN/UVLO rising 1.2 1.25 1.3 V VENF VEN/UVLO falling 1.1 1.15 1.2 VEN-TRUESD VEN/UVLO falling, true shutdown 0.7 EN/UVLO Leakage Current IEN VEN/UVLO = 1.3V, TA = +25°C -100 +100 nA POWER MOSFETs High-Side pMOS On-Resistance RDS-ONH ILX = 0.1A (sourcing) 1.5 2.7 5.1 Ω Low-Side nMOS On-Resistance RDS-ONL ILX = 0.1A (sinking) 0.8 1.4 2.6 Ω LX Leakage Current ILX-LKG VEN = 0V, TA = +25°C, VLX = (VGND + 1V) to (VIN - 1V) -1 +1 ?A ??

2 www.maximintegrated.com/cn Note 1: Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a four-layer board. For detailed information on package thermal considerations, refer to www.maximintegrated.com/cn/app-notes/index.mvp/id/4083. Absolute Maximum Ratings Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Package Thermal Characteristics Electrical Characteristics (VIN = 24V, VGND = 0V, VVOUT = 3.3V, VFB = 0.85V, VEN/UVLO = 1.5V, RT/SYNC = 191kΩ, LX = SS = MODE = RESET = uncon- nected;

TA = TJ = -40°C to +125°C, unless otherwise noted. Typical values are at TA = +25°C. All voltages are referenced to GND, unless otherwise noted) (Note 2) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS SOFT-START (SS) Soft-Start Time tSS SS = unconnected 4.4 5.1 5.8 ms SS Charging Current ISS 4.7

5 5.3 ?A FEEDBACK (FB) FB Regulation Voltage VFB-REG MODE = GND 0.786 0.8 0.814 V MODE = unconnected 0.786 0.812 0.826 FB Input Leakage Current IFB VFB = 1V, TA = 25°C -100 +100 nA CURRENT LIMIT Peak Current-Limit Threshold IPEAK-LIMIT

185 210

235 mA Negative Current-Limit Threshold ISINK-LIMIT VMODE = GND

79 105

130 mA VMODE = unconnected 0.01 PFM Current Level IPFM VMODE = unconnected

50 72

90 mA OSCILLATOR (RT/SYNC) Switching Frequency fSW RRT = 422kΩ

90 100

111 kHz RRT = 191kΩ

205 220

235 RRT = 130kΩ

295 319

340 RRT = 69.8kΩ

540 592

638 RRT = 45.3kΩ

813 900

973 RRT = 19.1kΩ 1.86 2.08 2.3 MHz Switching Frequency Adjustable Range See the Switching Frequency (RT/ SYNC) section for details

100 2200 kHz SYNC Input Frequency 1.1 x fSW

2200 kHz SYNC Pulse Minimum Off-Time

40 ns SYNC Rising Threshold VSYNC-H

1 1.22 1.44 V Hysteresis VSYNC-HYS 0.115 0.18 0.265 No of SYNC Pulses to Enable Synchronization

1 Cycles TIMING Minimum On-Time tON-MIN

46 82

128 ns Maximum Duty Cycle DMAX fSW ≤ 600kHz, VFB = 0.98 x VFB-REG

90 94

98 % fSW >

600kHz, VFB = 0.98 x VFB-REG

87 92 ??

3 www.maximintegrated.com/cn Electrical Characteristics (continued) (VIN = 24V, VGND = 0V, VVOUT = 3.3V, VFB = 0.85V, VEN/UVLO = 1.5V, RT/SYNC = 191kΩ, LX = SS = MODE = RESET = uncon- nected;

TA = TJ = -40°C to +125°C, unless otherwise noted. Typical values are at TA = +25°C. All voltages are referenced to GND, unless otherwise noted) (Note 2) Note 2: Actual IQ-PFM in the application circuit is higher due to additional current in the output voltage feedback resistor divider. For example, IQ-PFM (MODE = unconnected) = 26?A for Figure 6, 22?A for Figure 7, and 78?A for Figure 11. Note 3: All limits are 100% tested at +25°C. Limits over temperature are guaranteed by design. PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS RESET FB Threshold for RESET Rising VFB-OKR VFB rising