LMR38010

Part: LMR38010FDDAR — Texas Instruments

Type: Synchronous Buck Converter (SIMPLE SWITCHER, FPWM variant)

Description: 4.2–80 V input, 1 A synchronous buck converter with 40 μA non-switching quiescent current, 200 kHz–2.2 MHz adjustable switching frequency and 1 V ±1% feedback reference.

Operating Conditions:

• Supply voltage: 4.2–80 V (input range after start-up)
• Operating junction temperature: -40 to 150 °C
• Output voltage range (adjustable): 1–75 V
• Switching frequency: 200–2200 kHz; sync range 300–2100 kHz
• Output DC current: 0–1 A

Absolute Maximum Ratings:

• VIN to PGND: -0.3 to 85 V
• SW to PGND: -0.3 to 85 V (-5.0 to 85.3 V for transients under 10 ns)
• EN to PGND: -0.3 to VIN+0.3 V
• FB, RT/SYNC to PGND: -0.3 to 5.5 V
• PGOOD to PGND: -0.3 to 20 V
• Junction temperature: -40 to 150 °C
• Storage temperature: -65 to 150 °C

Key Specs:

• Input operating voltage: 4.2 V max needed to start up; 3.8 V max once operating
• Non-switching quiescent current: 40 μA typ (VEN = 3.3 V, PFM variant only)
• Shutdown quiescent current: 3 μA typ, 10 μA max (VEN = 0 V)
• Feedback reference: 1 V typ; 0.99–1.01 V (TJ = 25 °C, VIN = 4.2–80 V, FPWM); 0.985–1.015 V over temperature
• Enable threshold: 1.1–1.4 V rising (1.25 V typ); 0.95–1.22 V falling (1.10 V typ)
• High-side current limit: 1.3 / 1.6 / 1.9 A (min/typ/max)
• Low-side current limit: 0.9 / 1.2 / 1.5 A (min/typ/max)
• Negative current limit (FPWM variant): -0.5 A typ
• High-side MOSFET RDS(on): 303 mΩ typ
• Thermal resistance RθJA: 42.9 °C/W (DDA package); 29 °C/W with TI EVM board

Features:

• Functional Safety-Capable
• Ultra-low 40 μA operating quiescent current
• Greater than 1.5 mm spacing between VIN and GND pins
• Frequency synchronization to an external clock
• 97% maximum duty cycle
• Start-up with pre-biased output
• Precision enable and power-good flag with built-in filtering and delay
• Integrated compensation network and synchronous rectification
• Cycle-by-cycle current limit, hiccup short-circuit protection, thermal shutdown
• FPWM operation, no spread spectrum on this variant

Applications:

• Industrial transport
• Wireless infrastructure and networking
• Power delivery
• Factory automation and control

Package:

• DDA, 8-pin HSOIC with PowerPAD (4.89 mm × 3.90 mm)

• Functional Safety-Capable
• -Documentation available to aid functional safety system design
• Configured for rugged industrial applications
• -4.2-V to 80-V input voltage range
• -1-A continuous output current
• -Ultra-low 40-μA operating quiescent current
• -> 1.5-mm distance between VIN and GND pin
• -200-kHz to 2.2-MHz adjustable switching frequency
• -Frequency synchronization to external clock
• -Spread spectrum option for reduced EMI
• -97% maximum duty cycle
• -Support start-up with pre-biased output
• -±1.0% tolerance voltage reference at room temperature
• -Precision enable
• -Easy to use device with integrated compensation network enabling low BOM count
• -Integrated synchronous rectification
• -8-pin HSOIC with PowerPAD ™ integrated circuit package
• -PFM and forced PWM (FPWM) options
• -Available in 2-A, LMR38020
• Create a custom design using the LMR38010 with the WEBENCH ® Power Designer

• Industrial transport
• Wireless infrastructure and networking
• Power delivery
• Factory automation and control

Figure 6-1. DDA Package, 8-Pin HSOIC (Top View)

Table 6-1. Pin Functions

Limits apply over operating junction temperature (T J ) range of -40°C to +150°C, unless otherwise stated. Minimum and Maximum limits (1) are specified through test, design or statistical correlation. Typical values represent the most likely parametric norm at TJ = 25°C, and are provided for reference purposes only. Unless otherwise stated, the following conditions apply: V IN = 24 V.

Over junction temperature range of -40°C to 150°C (unless otherwise noted) (1)

Over the recommended operating junction temperature range of -40°C to 150°C (unless otherwise noted) (1)

The LMR38010 step-down DC-to-DC converter is typically used to convert a higher DC voltage to a lower DC voltage with a maximum output current of 1 A. The following design procedure can be used to select components for the LMR38010. Alternately, use the WEBENCH Design Tool to generate a complete design. This tool uses an iterative design procedure and has access to a comprehensive database of components. This allows the tool to create an optimized design and allows the user to experiment with various options.

• (1) For all available packages, see the orderable addendum at the end of the data sheet.
• (2) The package size (length × width) is a nominal value and includes pins, where applicable.

Efficiency vs Output Current VOUT = 5 V, 400 kHz