ISL78226 Datasheet, PDF (1/94 Pages) Intersil Corporation – Cycle-by-cycle peak current limiting

DATASHEET
6-Phase 12V/48V Bidirectional Synchronous PWM
Controller
ISL78226
The ISL78226 is a 6-phase, bidirectional, synchronous PWM
controller designed to perform power conversion between 12V
and 48V buses up to 3.75kW at >95% conversion efficiency.
One ISL78226 supports both Buck and Boost power
conversion enabling a compact and robust design with
minimum components.
ISL78226 regulates both voltage and current to control power
transfer from bus to bus. The multiphase architecture uses
interleaved timing to support up to six parallel power stages
per ISL78226. By interleaving the power stages, the ripple
frequency is multiplied, reducing input and output ripple
voltage and current. Lower ripple results in fewer input/output
capacitors and therefore, lower component cost and smaller
circuit implementation.
The IC is designed to be interleaved in a master/slave
architecture to be scaleable for higher power. Also integrated
within the device is a dual-output Flyback controller that
generates both a 12V supply for the power stage FET drivers as
well as a 6V supply for the ISL78226 from either of the two
buses. A 200mA auxiliary linear regulator is provided to supply
a local microcontroller or interface devices.
A PMBus interface provides system control and diagnostics to
support functional safety requirements. This digital interface
offers the system controller the ability to program operating
modes, voltage and current limit warning, protection
thresholds, individual fault response, and rapid fault condition
detection.
Related Literature
• For a full list of related documents, visit our website
- ISL78226 product page
Features
• 6-phase bidirectional synchronous 12V to 48V controller
• Master/slave architecture supports up to 4 ICs in parallel
• Voltage and current regulation
• Phase dropping facilitated with companion FET driver
• Average phase-to-phase current balancing
• Average current output with ±1.5% accuracy
• Supply and clock redundancy for functional safety
• Cycle-by-cycle peak current limiting
• Cycle-by-cycle negative current limiting
• Digitally programmable average current limit
• Analog/digital control of output voltage
• PMBus for status monitoring and fault response control
• Selectable phase dropping and diode emulation for
light-load efficiency improvement
• Comprehensive protection with selectable hiccup or
latch-off fault responses
• Digitally programmable warning and fault thresholds
• Dual-output Flyback controller
• 200mA adjustable output linear regulator
• 10mmx10mm 64-TQFP with exposed pad thermal interface
• AEC-Q100 Grade 1
Applications
• Automotive Bidirectional DC/DC Converter
• Bidirectional DC/DC for smart grid
97
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93
BAT48 = 36V
BAT48 = 48V
92
BAT48 = 56V
91
90
0
20 40 60 80 100 120 140 160 180 200
BAT12 LOAD CURRENT (A)
FIGURE 1A. BUCK MODE, DE MODE, PHASE-DROP ENABLED
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BAT12 = 10V
BAT12 = 12V
92
BAT12 = 16V
91
90
0
5
10
15
20
25
30
35
BAT48 LOAD CURRENT (A)
FIGURE 1B. BOOST MODE, DE MODE, PHASE-DROP ENABLED
FIGURE 1. EFFICIENCY CURVES UP TO 6-PHASE
November 7, 2016
1
FN8887.0
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
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