Analog Devices LT8604C | Demoboard DC2867A

Description

Demonstration circuit 2867A features the LT8604C, a high efficiency 42V, 120mA synchronous step-down regulator in 12-Lead 2mm × 2mm LQFN package. The demo board is designed for 120mA at 5V output from a 5.8V to 42V input, with the switching frequency programmed at 2MHz. The wide input range allows a variety of input sources, such as automotive batteries and industrial supplies.The LT8604C is a compact high efficiency, and high frequency synchronous monolithic step-down switching regulator, with soft-start capacitor, compensation network, BST and INTVCC capacitors, all packed into a 2mm by 2mm package.The switching frequency can be programmed via an oscillator resistor over a wide range from 200kHz to 2.2MHz, or sync to external clock through SYNC/MODE pin. Peak current mode control with minimum on-time of as small as 35ns allows high step-down conversion even at high frequency.The operation mode can be configured via the SYNC/MODE pin for forced continuous mode, Burst Mode® operation, or spread spectrum mode. While in Burst Mode operation, the current limit of the LT8604C top switch is approximately 215mA. The switching frequency will be far lower than the RT programmed frequency, and correspondingly much higher efficiency over wide loads ranges.The low quiescent current and high efficiency in Burst Mode make it an ideal solution for applications requiring highest efficiency at very light load conditions, such as automotive housekeeping supplies, industrial sensors, flow meters, Internet of Things, and battery powered portable instruments.The demo board 2867A has an EMI filter installed. The EMI performance of the board running in SSFM mode is shown in Figure 2 of the demo manual, where the red lines are CISPR25 Class 5 average limits. The circuit passes the average limit with a wide margin.The LT8604/LT8604C data sheet gives a complete description of the part, operation, and application information. The data sheet must be read in conjunction with the 2867A demo manual. Contact ADI applications engineer for technical support.

Features

• High Efficiency 2MHz Synchronous Operation

• 90% Efficiency at 50mA, 12VIN to 5VOUT

• Pin Selectable Forced Continuous or Burst Mode® Operation (LT8604C Only)
• Ultralow Quiescent Current Burst Mode Operation
• < 2.5μA IQ Regulating 24VIN to 3.3VOUT
• Output Ripple < 10mVP-P
• Wide Input Voltage Range: 3.2V to 42V
• Fast Minimum Switch-On Time: 35ns
• Adjustable (All) and Synchronizable (LT8604C Only) Switching Frequency: 200kHz to 2.2MHz
• Accurate 1V Enable Pin Threshold (All) with Adjustable Hysteresis (LT8604C Only)
• Internal Compensation
• Output Soft-Start and Tracking
• Small 12-Lead 2mm × 2mm LQFN (LT8604C) and Small 10-Lead 3mm × 2mm Side-Wettable DFN Package
• AEC-Q100 Qualified for Automotive Applications (LT8604)

Typical applications

• 4mA to 20mA Current Loops, Flow Meters
• Industrial Internet of Things
• Automotive Housekeeping Supplies
• Industrial Sensors

More information

• Datasheet
• IC product information