0
ACTIVE
Rating |
Catalog |
Topology |
Boost, Flyback, SEPIC |
Vin (max) (V) |
45 |
Vin (min) (V) |
1.5 |
Vout (max) (V) |
48 |
Vout (min) (V) |
1.5 |
Switch current limit (typ) (A) |
7.5 |
Features |
Enable, Frequency synchronization, Nonsynchronous rectification, Power good, Spread Spectrum, UVLO adjustable |
EMI features |
Frequency Dithering, Spread Spectrum |
Control mode |
current mode |
Operating temperature range (°C) |
-40 to 125 |
Iq (typ) (A) |
0.00067 |
Duty cycle (max) (%) |
93 |
TI functional safety category |
Functional Safety-Capable |
WQFN (RTE)-16-9 mm² 3 x 3
The LM5157 device is a wide input range, non-synchronous boost converter with integrated 50-V power switch.
The device can be used in boost, SEPIC, and flyback topologies. The device can start up from a single-cell battery with a minimum of 2.9 V. It can operate with an input supply voltage as low as 1.5 V if the BIAS pin is greater than 2.9 V.
The BIAS pin operates up to 45 V (50-V absolute maximum). The switching frequency is dynamically programmable with an external resistor from 100 kHz to 2.2 MHz. Switching at 2.2 MHz minimizes AM band interference and allows for a small solution size and fast transient response. To reduce the EMI of the power supply, the device provides a selectable Dual Random Spread Spectrum, which reduces the EMI over a wide frequency range.
The device features an accurate peak current limit over the input voltage, which avoids overdesigning power inductor. Low operating current and pulse-skipping operation improve efficiency at light loads.
The device has built-in protection features such as overvoltage protection, line UVLO, thermal shutdown, and selectable Hiccup mode overload protection. Additional features include low shutdown I Q, programmable soft start, precision reference, a power-good indicator, and external clock synchronization.