DATASHEET
ISL81601
60V Bidirectional 4-Switch Synchronous Buck-Boost Controller
FN9299
Rev.2.00
Sep 19, 2018
The
ISL81601
is a true bidirectional 4-switch
synchronous buck-boost controller with peak and
average current sensing and monitoring at both ends. Its
wide input and output voltage ranges make it suitable for
industrial, telecommunication, and after-market
automotive applications.
The ISL81601 uses the proprietary buck-boost control
algorithm with valley current modulation for Boost mode
and peak current modulation for Buck mode control.
The ISL81601 has four independent control loops for input
and output voltages and currents. Inherent peak current
sensing at both ends and cycle-by-cycle current limit of
this family of products ensures high operational reliability
by providing instant current limit in fast transient
conditions at either ends and in both directions. It also has
two current monitoring pins at both input and output to
facilitate Constant Current (CC) limit and other system
management functions. CC operation down to low
voltages avoids any runaway condition at over load or
short-circuit conditions. In addition to multilayer
overcurrent protection, it also provides full protection
features such as OVP, UVP, OTP, and average and peak
current limit on both input and output to ensure high
reliability in both unidirectional and bidirectional
operation. The IC is packaged in a space conscious 32 Ld
5mm x5mm QFN package or easy to assemble
4.4mmx9.7mm 38 Ld HTSSOP package. Both packages
use an EPAD to improve thermal dissipation and noise
immunity. Low pin count, fewer external components, and
default internal values make the ISL81601 an ideal
solution for quick to market simple power supply designs.
The unique DE/Burst mode at light-load dramatically
lowers standby power consumption with consistent output
ripple over different load levels.
Features
• Single inductor 4-switch buck-boost controller
• On-the-fly bidirectional operation with independent
control of voltage and current on both ends
• Proprietary algorithm for smoothest mode transition
• MOSFET drivers with adaptive shoot-through
protection
• Wide input voltage range: 4.5V to 60V
• Wide output voltage range: 0.8V to 60V
• Supports pre-biased output with SR soft-start
• Programmable frequency: 100kHz to 600kHz
• Supports parallel operation current sharing with
cascade phase interleaving
• External sync with clock out or frequency dithering
• External bias for higher efficiency supports 8V - 36V
input
• Output and input current monitor
• Selectable PWM mode operation between
PWM/DE/Burst modes
• Accurate EN/UVLO and PGOOD indicator
• Low shut down current: 2.7µA
• Complete protection: OCP, SCP, OVP, OTP, and UVP
• Dual-level OCP protection with average current
and pulse-by-pulse peak current limit
• Selectable OCP response with either hiccup or
constant current mode
• Negative pulse-by-pulse peak current limit
Related Literature
For a full list of related documents, visit our website:
•
ISL81601
product page
VIN
R
s_in
Q1
L
PH1
LG1
Q2
Q3
PH2
LG2
Q4
R
s_out
VOUT
Applications
• Battery backup
• UPS/storage systems
• Battery powered industrial applications
• Renewable energy
• Aftermarket automotive
• Redundant power supplies
• Robot and drones
• Medical equipment
• Building and industrial automation
• Security surveillance
UG1
UG2
Figure 1. Buck-Boost Power Train Topology
FN9299 Rev.2.00
Sep 19, 2018
Page 1 of 53
ISL81601
Contents
1.
1.1
1.2
1.3
1.4
1.5
2.
2.1
2.2
2.3
2.4
3.
4.
4.1
4.2
4.3
4.4
4.5
4.6
4.7
4.8
4.9
4.10
4.11
4.12
4.13
4.14
5.
5.1
5.2
5.3
5.4
5.5
6.
6.1
6.2
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Typical Application Schematics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Ordering Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Pin Configurations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Pin Descriptions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Specifications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Absolute Maximum Ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Thermal Information. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Recommended Operating Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Electrical Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
13
13
14
14
Typical Performance Curves. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
General Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Internal 8V Linear Regulator (VDD), External Bias Supply (EXTBIAS),
and 5V Linear Regulator (VCC5V) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Enable (EN/UVLO) and Soft-Start Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Tracking Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Control Loops . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Buck-Boost Conversion Topology and Control Algorithm . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Light-Load Efficiency Enhancement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Prebiased Power-Up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Frequency Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Phase Lock Loop (PLL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Frequency Synchronization and Dithering. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Parallel Operation Current Sharing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Gate Drivers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Power-Good Indicator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
26
26
26
28
28
32
35
36
37
37
38
39
41
42
Protection Circuits. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
Input Undervoltage Lockout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
VCC5V Power-On Reset (POR) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Overcurrent Protection (OCP) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Overvoltage Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Over-Temperature Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
43
43
43
44
44
Layout Guidelines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
Layout Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
General EPAD Design Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
FN9299 Rev.2.00
Sep 19, 2018
Page 3 of 53
京公网安备 11010802033920号
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