LM5168-Q1, LM5169-Q1
SNVSBZ3 – JUNE 2021
LM5169-Q1/LM5168-Q1 0.65-A/0.3-A, 120-V, Step-Down Converter with Fly-Buck™
Converter Capability
1 Features
3 Description
•
AEC-Q100-qualified for automotive applications
– Device temperature grade 1: –40°C to +125°C,
ambient temperature range
The LM5169-Q1 and LM5168-Q1 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-Q1
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.
•
Designed for reliable and 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 automotive HEV/EV power
supplies
– 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
•
With integrated high-side and low-side power
MOSFETs, the LM5169-Q1 delivers up to 0.65-A
of output current and the LM5168-Q1 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-Q1 is available in
FPWM or Auto mode operation. FPWM mode ensures
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-Q1,
LM5163-Q1, 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-Q1
PACKAGE(1)
BODY SIZE (NOM)
SO PowerPAD (8)
4.89 mm × 3.90 mm
LM5168-Q1
(1) For all available packages, see the orderable addendum at
the end of the data sheet.
2 Applications
•
•
•
•
Communications – brick power module
Industrial battery pack (≥ 10 S)
Battery pack – e-bike/e-scooter/LEV
HEV/EV – battery management system
D1
LO
VIN
VOUT
VOUT2
VIN
SW
COUT2
CA
RA
CBST
CIN
RFB1
T1
EN/UVLO
RT
BST
FB
VIN
VOUT1
COUT
VIN
SW
CB
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. ADVANCE INFORMATION for preproduction products; subject to change
without notice.