LINEAR LTC3890 User's Manual
Summary
Engineers require dependable power solutions with these high-performance converters and protective controllers. The technology details robust dual-output DC/DC conversion (e.g., 9V–60V down to stable 3.3V and 8.5V) that achieves up to 99% efficiency while simplifying complex designs. Additionally, specialized integrated circuits provide critical overvoltage and overcurrent protection, automatically isolating components within microseconds. Ideal for developing sophisticated electronic systems, this manual offers deep technical insights into maximizing power efficiency, stability, and longevity across demanding voltage ranges.
Page 1 Text Content
design ideas
Dual Output High Efficiency Converter Produces 3.3V and 8.5V Outputs from a 9V to 60V Rail Victor Khasiev
The LTC3890 dual output VIN 9V TO 60V 22µF
DC/DC controller brings 1µF 50V
VIN INTVCC
EF FI CI EN CY
a unique combination of Si 7850DP TG1 TG2 Si 7850DP
high performance features BOOST1 BOOST2
SW1 SW2
to applications that require
BG1 BG2 Si 7850DPSi 7850DP
LTC3890
low voltage outputs from PGND
high voltage inputs. It can SENSE1+ SENSE2+
produce two output voltages
VOUT1 SENSE1– SENSE2– VOUT2 ranging from 0.8V to 24V 3.3V VFB1 VFB2 8.5V 5A 100k 3A
ITH1 ITH2 100k
from an input voltage of 4V 1000p FCOUT1 470p F COUT2
TRACK/SS1 SGND TRACK/SS2
to 60V. It is also very efficient, 31.6k 34.8k 34.8k
with a no-load quiescent
= DFLS1100 = 6TPE150
current of only 50µA.
Figure 1. High efficiency dual 8.5V/3.3V output step-down converter
Many high-input-voltage step-down
EF FI CI EN CY
DC/DC converter designs use a transformer- FEATURE RICH applications, adjustable soft-start or volt- based topology or external high side The LTC3890 is a high performance age tracking and selectable continuous, drivers to operate from up to 60VIN. synchronous buck DC/DC controller pulse-skipping or Burst Mode operation Others use an intermediate bus converter with integrated N-channel MOSFET driv- with a no-load quiescent current of only requiring an additional power stage. ers. It uses a current mode architecture 50µA. These features, combined with a However, the LTC3890 simplifies design, and operates from a phase-lockable minimum on-time of just 95ns, make this with its smaller solution size, reduced fixed frequency from 50k Hz to 900k Hz. controller an ideal choice for high step- cost and shorter development time The device features up to 99% duty down ratio applications. Power loss and compared to other design alternatives. cycle capability for low voltage dropout
(continued on page 35)
10VIN
VOUT1 50m V/DIV
30VIN
60VIN
ILOAD1 2A/DIV
VIN = 36V
1ms/DIV
ILOAD1 = 1A TO 5A LOAD CURRENT (A) LOAD CURRENT (A)
Figure 2. Transient response of 3.3V channel Figure 3. Efficiency of the converter in Figure 1 for Figure 4. Efficiency of the LTC3890 configured as a
the VOUT2 8.5V channel 2-phase single output of 8.5V at up to 6A
July 2010 : LT Journal of Analog Innovation | 33
Page Summary Contents For LINEAR LTC3890 User's Manual
Manual Details
| Brand | Linear |
|---|---|
| Pages | 2 |
| File Size | 745.31 KB |
| Published | June 19, 2026 |
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Frequently Asked Questions
What input voltage range can the LTC3890 operate from?
It operates from an input voltage ranging from 4V to 60V.
How many output voltages does the LTC3890 provide?
The device features two independent output voltages: one at 8.5V and another at 3.3V.
Does the device offer low-power modes?
It has a no-load quiescent current of only 50µA, making it efficient for low power applications.
What are some key features distinguishing the LTC3890 design?
The LTC3890 simplifies high step-down ratio DC/DC converter designs by reducing solution size and development costs compared to alternatives.