SM72295

SM72295 Photovoltaic Full Bridge Driver February 25, 2011 SM72295 Photovoltaic Full Bridge Driver General Description The SM72295 is designed to drive 4 discrete N type MOSFET’s in a full bridge configuration. The drivers provide 3A of peak current for fast efficient switching and integrated high speed bootstrap diodes. Current sensing is provided by 2 transconductance amplifiers with externally programmable gain and filtering to remove ripple current to provide average current information to the control circuit. The current sense amplifiers have buffered outputs available to provide a low impedance interface to an A/D converter if needed. An externally programmable input over voltage comparator is also included to shutdown all outputs. Under voltage lockout with a PGOOD indicator prevents the drivers from operating if VCC is too low. Features ■ ■ ■ ■ ■ ■ Renewable Energy Grade Dual Half Bridge MOSFET Drivers Integrated 100V bootstrap diodes Independent High and Low driver logic inputs Bootstrap supply voltage range up to 115V DC Two current sense amplifiers with externally programmable gain and buffered outputs ■ Programmable over voltage protection ■ Supply rail under-voltage lockouts with power good indicator Package ■ SOIC-28 Typical Application Circuit 30134101 © 2011 National Semiconductor Corporation 301341 www.national.com SM72295 Connection Diagram 30134116 Top View SOIC-28 Ordering Information Order Number SM72295X SM72295E Description 28L SOIC WIDE 28L SOIC WIDE NSC Package Drawing M28B M28B Supplied As 1000 Units in Tape and Reel 250 Units in Tape and Reel www.national.com 2 SM72295 Pin Descriptions Pin 5 23 21,25 26,20 Name AGND PGND VCCA, VCCB HBA, HBB HOA, HOB HSA, HSB Description Analog ground Power ground return Positive gate drive supply High side gate driver bootstrap rail. High side gate driver output High side MOSFET source connection Application Information Ground return for the analog circuitry. Tie to the ground plane under the IC Ground return for the LO drivers. Tie to the ground plane under the IC Locally decouple to PGND using low ESR/ESL capacitor located as close to IC as possible. Connect the positive terminal of the bootstrap capacitor to HB and the negative terminal to HS. The bootstrap capacitor should be placed as close to IC as possible. Connect to gate of high side MOSFET with a short low inductance path. Connect to bootstrap capacitor negative terminal and the source of the high side MOSFET. The inputs have TTL type thresholds. Unused inputs should be tied to ground and not left open. The inputs have TTL type thresholds. Unused inputs should be tied to ground and not left open. Connect to the gate of the low side MOSFET with a short low inductance path. Bypass with 0.1uF. Reference for over voltage shutdown and IOUT/IIN clamp Open drain output with an internal pull-up resistor to VDD indicating VCC is in regulation. PGOOD low implies VCC is out of regulation. Open drain output with an internal pull-up resistor to VDD indicating OVS >VDD. OVP is low when OVS>VDD. Buffered IOUT. Buffered IIN. 27, 19 28, 18 7, 8 6, 9 24, 22 17 10 15 11 4 1 2 3 HIA, HIB High side driver control input LIA, LIB LOA, LOB VDD Low side driver control input Low side gate driver output 3.3V or 5V regulator output PGOOD Power good indicator output OVP BOUT BIN SIA S0A IIN Over voltage indicator output Buffered IOUT Buffered IIN Sense high input for input current Tie to positive side of the current sense resistor through an external gain sense transconductance amplifier programming resistor (RI). Amplifier transconductance is 1/RI. Sense low input for input current Tie to negative side of the current sense resistor through an external gain sense transconductance amplifier programming resistor. Amplifier transconductance is 1/RI. Output for current sense transconductance amplifier Output of the input current sense amplifier. Requires an external resistor to ground (RL). Gain is RL/RI, where RI is the external resistor in series with the SIA pin. 14 13 12 SIB S0B IOUT Sense high input for output current Tie to positive side of the current sense resistor through an external gain sense amplifier programming resistor (RI). Amplifier transconductance is 1/RI. Sense low input for output current Tie to negative side of the current sense resistor through an external gain sense amplifier programming resistor. Amplifier transconductance is 1/RI. Output for current sense comparator. Sense input for over voltage Output of the output current sense amplifier. Requires an external resistor to ground (RL). Gain is RL/RI, where RI is the external resistor in series with the SIB pin. Requires an external resistor divider. VDD is the reference voltage. 16 OVS 3 www.national.com SM72295 Absolute Maximum Ratings (Note 1) If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications. VCCA, VCCB VDD HBA to HSA, HBB to HSB LIA,LIB,HIA,HIB,OVS LOA,LOB HOA,HOB SIA,SOA,SIB,SOB SIA to SOA, SIB to SOB HSA,HSB (note 5) HBA, HBB PGOOD, OVP IIN, IOUT -0.3 to 14V -0.3 to 7V -0.3 to 15V -0.3 to 7V -0.3 to VCC+ 0.3V HS–0.3 to HB + 0.3V -0.3 to 100V -0.8 to 0.8V -5 to 100V 115V -0.3 to VDD -0.3 to VDD BIN, BOUT Junction Temperature Storage Temperatue Range ESD Rating Human Body Model -0.3 to VDD 150°C -55°C to +150°C 2 kV Recommended Operating Conditions VCCA,VCCB VDD SI, SO common mode HS (Note 5) HBA, HBB HS Slew Rate Junction Temperature +8V to +14V +3V to 7V VDD+1V to 100V -1V to 100V HS+7V to HS+14V