ADI LTC3838IUHF#TRPBF

Dual Channel, Fast, Accurate Step-Down DC/DC Controller with Differential Output Voltage Sensing

Wide V_IN Range: 4.5V to 38V, V_OUT: 0.6V to 5.5V ±0.67% Output Voltage Accuracy, Overtemperature Protection, Differential Output Voltage Sensing Allows Up to ±500mV Line Loss on Channel 1 Remote Ground ±1% Independent Channel 2 Controlled On-Time, Valley Current Mode Control Fast Load Transient Response Detect Transient (DTR) Reduces V_OUT Overshoot Frequency Programmable from 200kHz to 2MHz, Synchronizable to External Clock t_ON(MIN) = 30ns, t_OFF(MIN) = 90ns RSENSE or Inductor DCR Current Sensing Overvoltage Protection and Current Limit Foldback Power Good Output Voltage Monitoring

The LT3838 is a dual channel PolyPhase synchronous step-down DC/DC switching regulator controller. Both independent channels drive all N-channel power MOSFETs. The controlled on-time, valley current mode control architecture allows fast transient response and constant frequency switching during steady-state operation, independent of V_IN, V_OUT, and load current. Its load release transient detection feature significantly reduces overshoot at low output voltages.

Differential output voltage sensing combined with a high accuracy internal reference provides ±0.67% output regulation for Channel 1 even with up to ±500mV offset between the remote output ground and local ground. Channel 2 can provide an independent ±1% output, or operate as a PolyPhase channel alongside Channel 1 of this controller for a single output voltage.

Switching frequency is programmable via an external resistor from 200kHz to 2MHz and can be synchronized to an external clock. Very low t_ON and t_OFF times allow duty cycles approaching 0% and approaching 100%, respectively. Voltage tracking soft-start and multiple protection features are provided.

• Wide input voltage range: 4.5V to 38V, output voltage range: 0.6V to 5.5V, output voltage accuracy ±0.67% over temperature
• Differential output voltage sensing, allows up to ±500mV line loss on Channel 1 remote ground
• Independent second channel output accuracy ±1%
• Controlled on-time, valley current mode control
• Fast load transient response
• Detect Transient Response (DTR) reduces output voltage overshoot
• Frequency programmable from 200kHz to 2MHz, synchronizable to external clock
• Minimum on-time tON(MIN) = 30ns, minimum off-time tOFF(MIN) = 90ns
• RSENSE or inductor DCR current sensing
• Overvoltage protection and current limit foldback
• Output voltage good monitoring
• Output voltage tracking and adjustable soft-start
• Thermally enhanced 38-pin (5mm x 7mm) QFN and TSSOP packages

• Distributed power systems
• Point-of-load converters
• Computing systems
• Data communication systems