LTM8049EY#PBF Dual SEPIC/Inverting μModule DC/DC Converter

1. Basic Overview

• Device Type: Dual SEPIC or Inverting μModule DC/DC Converter
• Manufacturer: Analog Devices
• Part Number: LTM8049EY#PBF
• Package: 77‑lead BGA, dimensions 15 mm × 9 mm × 2.42 mm
• Finish: SAC305, RoHS compliant (e4) with gold pad finish
• Temperature Grade: E‑grade; guaranteed 0°C to 125°C; performance over –40°C to 125°C assured by design
• MSL Rating: MSL 3
• Weight: 0.8 g
• Key Integration: Power devices, inductors, control circuitry, and passives integrated; minimal external components required

2. Key Features

• Dual independent switch‑mode power supplies
• Configurable as SEPIC or inverting topology
• Wide input voltage: 2.6 V to 20 V
• Output voltage:
• Output current: 1 A at 5 VOUT from 12 VIN; 0.25 A at 24 V/–24 V
• Switching frequency: 200 kHz to 2.5 MHz (resistor‑programmable or external sync)
• Power Good (PG) outputs for sequencing
• User‑configurable undervoltage lockout (UVLO)
• Soft‑start control via external capacitor
• Frequency synchronization input (SYNC) and clock output (CLKOUT)
• Thermal shutdown and overcurrent protection
• Low‑profile surface‑mount BGA for automated assembly

3. Absolute Maximum Ratings

• VINn, RUNn, PGn: 20 V
• SYNCn, FBXn: 5 V
• SSn: 2.5 V
• SHAREn: 2 V
• VOUTP (VOUTN = 0 V): 25 V
• VOUTN (VOUTP = 0 V): –25 V
• Maximum internal junction temperature: 125°C
• Storage temperature: –55°C to 125°C
• Maximum solder temperature: 260°C

4. Electrical Characteristics (TA = 25°C, unless noted)

表格

5. Thermal Specifications

• θJA: 16.2°C/W
• θJB: 3.8°C/W
• θJCtop: 8.8°C/W
• θJCbottom: 3.8°C/W
• θJCboard: 4.6°C/W
• Thermal shutdown: activates above 125°C; automatic recovery after cooling

6. Pin Functions Summary

• VIN1/VIN2: Input power; local bypass required
• VOUT1P/VOUT2P, VOUT1N/VOUT2N: Positive/negative outputs; grounding one sets topology
• RUN1/RUN2: Enable/disable; UVLO configuration
• RT1/RT2: Set switching frequency (resistor to GND)
• SS1/SS2: Soft‑start timing (capacitor to GND)
• SYNC1/SYNC2: External frequency synchronization
• FBX1/FBX2: Feedback for output voltage programming
• PG1/PG2: Open‑drain power‑good indicators
• CLKOUT1/CLKOUT2: Synchronization clock outputs
• SHARE1/SHARE2: Paralleling two outputs for higher current
• GND: System and thermal ground; must connect to VOUTP or VOUTN

7. Application Information

Topology Configuration

• SEPIC (positive output): Tie VOUTnN to GND
• Inverting (negative output): Tie VOUTnP to GND

Frequency Programming

• Formula: RT = (81.6 / fOSC) – 1 (fOSC in MHz, RT in kΩ)
• Recommended frequency: 200 kHz to 2.5 MHz

UVLO Configuration

• Single resistor: RUVLO1 = (VIN(TH) – 1.31 V) / 12.1 μA
• Two‑resistor for improved hysteresis stability

Capacitor Guidelines

• Input: 4.7 μF 25 V X5R/X7R ceramic (minimum)
• Output: X5R/X7R types; avoid Y5V/Z5U
• Bulk input capacitor recommended for hot‑plugging safety

PCB Layout

• Place CIN, COUT, RFB, RT close to device
• Large GND plane with thermal vias for heat dissipation
• Minimize loop areas to reduce EMI

8. Typical Applications

• Battery‑powered systems
• Local negative voltage regulators
• Low‑noise amplifier bias supplies
• Dual‑rail ±VOUT systems (e.g., ±5 V, ±12 V)
• Parallel outputs for higher output current

9. Ordering Information

• Part Number: LTM8049EY#PBF
• Package: 15 mm × 9 mm × 2.42 mm 77‑lead BGA
• Pad finish: SAC305 (RoHS)
• Temperature range: 0°C to 125°C (E‑grade)
• Not recommended for second‑side reflow; moisture‑sensitive device