LTC7802-3.3 Data Sheet (Rev. A)9/24/2020
Features and Benefits
- Wide Input Voltage Range: 4.5V to 40V
- Wide Output Voltage Range: 0.8V to 99% • VIN
- Low Operating IQ: 12μA (14V to 3.3V, Channel 1 On)
- Fixed 3.3V Output Voltage on Channel 1
- Spread Spectrum Operation
- RSENSE or DCR Current Sensing
- Out-of-Phase Controllers Reduce Required Input Capacitance and Power Supply Induced Noise
- Programmable Fixed Frequency (100kHz to 3MHz)
- Phase-Lockable Frequency (100kHz to 3MHz)
- Selectable Continuous, Pulse-Skipping, or Low Ripple, Burst Mode® Operation at Light Loads
- Very Low Dropout Operation: 99% Duty Cycle
- Power Good Output Voltage Monitors
- Output Overvoltage Protection
- Internal LDO Powers Gate Drive from VIN or EXTVCCC
- Low Shutdown IQ: 1.5μA
- Side Wettable 4mm × 5mm QFN-28 Package
- AEC-Q100 Qualified for Automotive Applications
The LTC7802-3.3 is a high performance dual step-down synchronous DC/DC switching regulator controller that drives all N-channel power MOSFET stages. Constant frequency current mode architecture allows a phase-lockable switching frequency of up to 3MHz. The LTC7802-3.3 operates from a wide 4.5V to 40V input supply range. Power loss and supply noise are minimized by operating the two controller output stages out-of-phase.
The very low no-load quiescent current extends operating runtime in battery powered systems. OPTI-LOOP compensation allows the transient response to be optimized over a wide range of output capacitance and ESR values. The LTC7802-3.3 features a precision 0.8V reference and power good output indicators. The MODE pin selects among Burst Mode operation, pulse-skipping mode, or continuous inductor current mode at light loads.
The LTC7802-3.3 additionally features spread spectrum operation which significantly reduces the peak radiated and conducted noise on both the input and output supplies, making it easier to comply with electromagnetic interference (EMI) standards.
- Automotive and Transportation
- Military / Avionics
Product Lifecycle Recommended for New Designs
This product has been released to the market. The data sheet contains all final specifications and operating conditions. For new designs, ADI recommends utilization of these products.
Evaluation Kits (1)
Demonstration circuit 2922A-A and 2922A-B are dual step-down DC/DC converters featuring the LTC7802 or LTC7802-3.3 PWM controllers. Both controller IC’s used on these demo boards are 40V Low IQ, Dual, 2-Phase Synchronous Step-Down Controllers with Spread Spectrum. And both demo boards operate over a 5V to 36V input voltage range and provide a 3.3V at 20A and 5V at 15A outputs.
The DC2922A-A uses the LTC7802 and has a resistor divider network to set the 3.3V output. The DC2922A-B uses the LTC7802-3.3 and has a fixed 3.3V output that does not require the resistor divider network.
Some of the key features of both boards include a FREQUENCY jumper for spread-spectrum or external clock option, and EXTVCC jumper for VOUT2, EXTVCC, or input derived VCC, a MODE jumper that allows the converter to run in FCM, pulse-skipping, or Burst Mode® operation and PGOOD signals for each output.
The two channels can be paralleled for higher output current. See the respective data sheets for more information on setting-up the board for paralleling both outputs. The LTC7802 and LTC7802-3.3 data sheets give a complete description of these devices, their operation and application information, and must be read in conjunction with the DC2922A demo manual prior to working on or modifying these demo circuits.
Documentation & Resources
Tools & Simulations
LTspice® is a powerful, fast and free simulation software, schematic capture and waveform viewer with enhancements and models for improving the simulation of analog circuits.
Models for the following parts are available in LTspice:
LTpowerCAD® is a power supply design program which selects power stage components, provides detailed power efficiency, shows quick loop Bode plot stability and load transient analysis, and can export to LTspice for simulation.
Design tools for the following parts are available in LTpowerCAD:
ADI has always placed the highest emphasis on delivering products that meet the maximum levels of quality and reliability. We achieve this by incorporating quality and reliability checks in every scope of product and process design, and in the manufacturing process as well. "Zero defects" for shipped products is always our goal.View our quality and reliability program and certifications for more information.
|Part Number||Material Declaration||Reliability Data||Pin/Package Drawing||CAD Symbols, Footprints & 3D Models|
|LTC7802EUFDM-3.3#PBF||Material Declaration||Reliability Data||28-Lead QFN (4mm x 5mm x 0.75mm w/ EP)|
|LTC7802EUFDM-3.3#TRPBF||Material Declaration||Reliability Data||28-Lead QFN (4mm x 5mm x 0.75mm w/ EP)|
|LTC7802HUFDM-3.3#WPBF||Material Declaration||Reliability Data||28-Lead QFN (4mm x 5mm x 0.75mm w/ EP)|
|LTC7802HUFDM-3.3#WTRPBF||Material Declaration||Reliability Data||28-Lead QFN (4mm x 5mm x 0.75mm w/ EP)|
|LTC7802IUFDM-3.3#WPBF||Material Declaration||Reliability Data||28-Lead QFN (4mm x 5mm x 0.75mm w/ EP)|
|LTC7802IUFDM-3.3#WTRPBF||Material Declaration||Reliability Data||28-Lead QFN (4mm x 5mm x 0.75mm w/ EP)|
|LTC7802JUFDM-3.3#WPBF||Material Declaration||Reliability Data||28-Lead QFN (4mm x 5mm x 0.75mm w/ EP)|
|LTC7802JUFDM-3.3#WTRPBF||Material Declaration||Reliability Data||28-Lead QFN (4mm x 5mm x 0.75mm w/ EP)|
|Wafer Fabrication Data|
Sample & Buy
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Pricing displayed is based on 1-piece. The USA list pricing shown is for budgetary use only, shown in United States dollars (FOB USA per unit), and is subject to change. International prices may vary due to local duties, taxes, fees and exchange rates.