DATA SHORT
ISL95521
Hybrid Power Boost (HPB) and Narrow VDC (NVDC) Configurations Combo
Battery Charger with SMBus Interface
The
ISL95521
is a highly versatile combo battery charger
configurable for operating as either a Hybrid Power Boost
(HPB) charger or a Narrow VDC (NVDC) charger, supporting 2-,
3-, or 4-cell batteries. Both configurations allow the battery to
work with the adapter together to supply the system load when
it exceeds the adapter capability, referred to as system Turbo
mode. The HPB charger configuration reverse-boosts battery
energy to the system bus to help the adapter provide system
power in Turbo mode. The NVDC charger configuration quickly
turns on BGATE to enable the battery to help the adapter
provide system power in Turbo mode.
The ISL95521 uses N-channel MOSFETs (NFETs) for all the
switches to achieve the best performance and lowest BOM
cost. The internal charge pump is capable of turning on all the
NFETs fast or slow depending on the circumstance or the need.
The ability to quickly turn on NFETs prevents system bus
voltage drop when the battery is suddenly removed in Turbo
mode or in battery learn mode.
The ISL95521 provides many protection features including a
PROCHOT# indicator for system low voltage, adapter
overcurrent, battery overcurrent or overheating, with an array
of SMBus programmable parameters for maximum flexibility.
The ISL95521 also features hardware based adapter current
limit and battery-current limit in addition to SMBus
programmable limits.
The ISL95521 provides high accuracy adapter current monitor,
battery current monitor, and system power monitor outputs. To
provide maximum flexibility for working with high power and
low power systems, the ISL95521 provides several
configurable current-sense resistor value options to achieve
the best trade-off of current sensing accuracy vs power loss.
The ISL95521 uses the Renesas Robust Ripple Regulator
(R3™) modulation scheme to provide excellent light-load
efficiency and fast dynamic response. The ISL95521 is
available in a 32 Ld 4mmx4mm QFN package.
FN8771
Rev 2.00
Jul.18.19
Features
• Configurable as an HPB charger or NVDC charger
• Compliant with Intel PROCHOT# and PSYS requirements
• Adapter current monitor and battery discharging current
monitor
• Uses NFET for all the switches
- Supports battery removal during battery learn mode
- Actively controlled inrush current to prevent FET damage
• SMBus programmable settings and high accuracy
• Comprehensive protection features;
- PROCHOT# indicator for system low voltage, adapter
overcurrent, battery overcurrent, and system overheating
- Hardware-based adapter current and battery current
limits
- Supports sudden battery removal in system Turbo mode
• 16 switching frequency options from 350kHz to 1MHz
• Low quiescent current
• SMBus and auto-increment I
2
C compatible
• Robust Ripple Regulator (R3) modulation scheme provides
excellent light-load efficiency and fast dynamic response
• 32 Ld 4mmx4mm QFN package
• Pb-free (RoHS compliant)
Applications
• Devices with rechargeable 2-, 3-, or 4-cell batteries
Related Literature
•
ISL95521
device page
VADP AFET
ADAPTER
SFET
VSYS
SYSTEM
ADAPTER
VADP
AFET
SFET
VSYS
SYSTEM
ASGATE CMSRC
UGATE
Q1
L
BFET
ASGATE CMSRC
UGATE
Q1
L
BFET
HPB
CHARGER
PROG
PHASE
LGATE
Q2
VBAT
NVDC
CHARGER
PROG
PHASE
LGATE
Q2
VBAT
BGATE
VBAT
BGATE
VBAT
FIGURE 1. HPB CHARGER CONFIGURATION
FIGURE 2. NVDC CHARGER CONFIGURATION
FN8771 Rev 2.00
Jul.18.19
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