LMR51406XFDBVR

Part: LMR51406, LMR51410 — Texas Instruments

Type: Synchronous Buck Converter

Description: Wide-VIN, easy-to-use synchronous buck converter capable of driving up to 0.6A (LMR51406) or 1A (LMR51410) load current, with a 4V to 42V input range and fixed 400kHz or 1.1MHz switching frequency.

Operating Conditions:

• Supply voltage: 4–42 V
• Operating temperature: -40 to +150 °C
• Output voltage: 0.8–28 V
• Output current: up to 0.6 A (LMR51406), up to 1 A (LMR51410)

Absolute Maximum Ratings:

• Max supply voltage: 45 V
• Max continuous current: 1 A (LMR51410)
• Max junction/storage temperature: 150 °C

Key Specs:

• VIN quiescent current (PFM variant): 26.5 μA (typ, V EN = 3V)
• VIN shutdown supply current: 0.8 μA (typ, V EN = 0V)
• Reference voltage (V FB): 0.8 V (typ)
• Switching frequency ("X" Version): 400 KHz (typ, CCM operation)
• Switching frequency ("Y" Version): 1.1 MHz (typ, CCM operation)
• High-side MOSFET on-resistance: 0.7 Ω (typ, V IN = 12V, T J = 25°C)
• Low-side MOSFET on-resistance: 0.36 Ω (typ, V IN = 12V, T J = 25°C)
• High-side peak current limit (LMR51410): 1.6 A (typ)
• Thermal shutdown threshold: 165 °C (typ)

Features:

• Functional Safety-Capable
• 4V to 42V input voltage range
• Input transient protection up to 50V
• 0.6A / 1A continuous output current
• Fixed 400kHz and 1.1MHz switching frequency
• -40°C to 150°C junction temperature range
• Monotonic start-up with prebiased output
• Short-circuit protection with hiccup mode
• Precision enable
• Integrated synchronous rectification
• Internal compensation
• PFM and forced PWM (FPWM) options

Applications:

• Major appliances
• PLC, DCS, and PAC
• Smart meters
• Power delivery

Package:

• DBV (SOT-23, 6) (2.90mm × 2.80mm)

• Functional Safety-Capable
• -Documentation available to aid functional safety system design
• Configured for rugged industrial applications
• -4V to 42V input voltage range
• -Input transient protection up to 50V
• -0.6A / 1A continuous output current
• -80ns minimum switching on time
• -Fixed 400kHz and 1.1MHz switching frequency
• --40°C to 150°C junction temperature range
• -98% maximum duty cycle
• -Monotonic start-up with prebiased output
• -Short-circuit protection with hiccup mode
• -Precision enable
• -±1.5% tolerance voltage reference
• Small design size and ease of use
• -Integrated synchronous rectification
• -Internal compensation for ease of use
• -SOT-23 package
• Various options in pin-to-pin compatible package -PFM and forced PWM (FPWM) options
• Pin-to-pin compatible with the LMR51610, LMR16006, LV2862, LMR50410, TPS560430 and LMR54410
• Create a custom design using the LMR514xx with the WEBENCH ® Power Designer

• Major appliances
• PLC, DCS, and PAC
• Smart meters

Simplified Schematic

Simplified Schematic

• Power delivery

Figure 5-1. 6-Pin SOT-23 DBV Package (Top View)

Table 5-1. Pin Functions

• (1) A = Analog, P = Power, G = Ground

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: VIN = 4V to 42V.

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 value of RθJA given in this table is only valid for comparison with other packages and cannot be used for design purposes. These values were calculated in accordance with JESD 51-7, and simulated on a 4-layer JEDEC board. They do not represent the performance obtained in an actual application. For example, with a 2-layer PCB, a R θJA = 95 °C /W can be achieved. For design information, see Maximum Output Current Versus Ambient Temperature.

The LMR514xx is a step-down DC-to-DC converter. The LMR51410 is typically used to convert a higher input voltage to a lower output DC voltage with a maximum output current of 1A. The LMR51406 is typically used to convert a higher input voltage to a lower output DC voltage with a maximum output current of 0.6A. The following design procedure can be used to select components for the LMR514xx.