LM5168
SNVSBS7 – DECEMBER 2021
LM5169/LM5168 0.65-A/0.3-A, 120-V, Step-Down Converter with Fly-Buck™ Converter
Capability
1 Features
3 Description
•
Designed for reliability in rugged applications
– Wide input voltage range of 6 V to 120 V
– Junction temperature range: –40°C to +150°C
– Fixed 3-ms internal soft-start timer
– Peak and valley current-limit protection
– Input UVLO and thermal shutdown protection
Suited for scalable industrial power supplies and
battery packs
– Low minimum on and off times of 50 ns
– Adjustable switching frequency up to 1 MHz
– Diode emulation for high light-load efficiency
– Auto mode with low quiescent current (< 10 µA)
– FPWM mode enables fly-buck capability
– 3-µA shutdown quiescent current
The LM5169 and LM5168 synchronous buck
converters are designed to regulate over a wide input
voltage range, minimizing the need for external surge
suppression components. A minimum controllable on
time of 50 ns facilitates large step-down conversion
ratios, enabling the direct step-down from a 48-V
nominal input to low-voltage rails for reduced system
complexity and solution cost. The LM5169 operates
during input voltage dips as low as 6 V, at nearly
100% duty cycle if needed, making it an excellent
choice for wide input supply range industrial and high
cell count battery pack applications.
•
With integrated high-side and low-side power
MOSFETs, the LM5169 delivers up to 0.65-A of
output current and the LM5168 delivers up to 0.3-
A of output current. A constant on-time (COT)
control architecture provides nearly constant switching
frequency with excellent load and line transient
response. The LM5169 is available in FPWM or auto
mode operation. FPWM mode provides forced CCM
operation across the entire load range supporting
isolated fly-buck operation. Auto mode enables ultra-
low IQ and diode emulation mode operation for high
light-load efficiency.
– Pin-to-pin compatible with LM5164, LM5163,
LM5017, and LM34927
Integration reduces solution size and cost
•
– COT mode control architecture
– Integrated 1.9-Ω NFET buck switch
– Integrated 0.71-Ω NFET synchronous rectifier
– 1.2-V internal voltage reference
– No loop compensation components
– Internal VCC bias regulator and boot diode
– Open-drain power-good indicator
– 8-pin SOIC package with PowerPAD™ with
30°C/W RθJA (EVM)
Device Information
PART NUMBER
LM5169(2)
PACKAGE(1)
BODY SIZE (NOM)
2 Applications
SO PowerPAD (8)
4.89 mm × 3.90 mm
•
•
•
Communications – brick power module
Industrial battery pack (≥ 10 S)
Battery pack – e-bike/e-scooter/LEV
LM5168
(1) For all available packages, see the orderable addendum at
the end of the data sheet.
(2) Preview
D1
LO
VIN
VOUT
VOUT2
VIN
SW
COUT2
CA
RA
CBST
CIN
RFB1
EN/UVLO
RT
BST
FB
T1
VIN
VOUT1
COUT
CB
VIN
SW
CA
RA
CBST
CIN
RFB1
EN/UVLO
RT
BST
FB
RT
RFB2
COUT1
CB
PGOOD
GND
RT
RFB2
GND
PGOOD
Typical Buck Application Circuit
Typical Fly-Buck Application Circuit
An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications,
intellectual property matters and other important disclaimers. PRODUCTION DATA.