ISL6277A Datasheet, PDF (1/38 Pages) Intersil Corporation – Multiphase PWM Regulator for AMD Fusion Mobile CPUs Using SVI 2.0

Multiphase PWM Regulator for AMD Fusion™ Mobile
CPUs Using SVI 2.0
ISL6277A
The ISL6277A is fully compliant with AMD Fusion™ SVI 2.0 and
provides a complete solution for microprocessor and graphics
processor core power. The ISL6277A controller supports two
Voltage Regulators (VRs) with three integrated gate drivers and
two optional external drivers for maximum flexibility. The Core VR
can be configured for 3-, 2-, or 1-phase operation while the
Northbridge VR supports 2- or 1-phase configurations. The two
VRs share a serial control bus to communicate with the AMD CPU
and achieve lower cost and smaller board area compared with
two-chip solutions.
The PWM modulator is based on Intersil’s Robust Ripple
Regulator R3 Technology™. Compared to traditional modulators,
the R3 modulator can automatically change switching frequency
for faster transient settling time during load transients and
improved light load efficiency.
The ISL6277A has several other key features. Both outputs
support DCR current sensing with single NTC thermistor for
DCR temperature compensation or accurate resistor current
sensing. Both outputs utilize remote voltage sense, adjustable
switching frequency, OC protection and power-good.
Applications
• AMD Fusion CPU/GPU core power
• Notebook computers
Features
• Supports AMD SVI 2.0 serial data bus interface
• Dual output controller with integrated drivers
- Two dedicated core drivers
- One programmable driver for either core or Northbridge
• Precision voltage regulation
- 0.5% system accuracy over-temperature
- 0.5V to 1.55V in 6.25mV steps
- Enhanced load line accuracy
• Supports multiple current sensing methods
- Lossless inductor DCR current sensing
- Precision resistor current sensing
• Programmable 1-, 2- or 3-phase for the core output and 1- or
2-phase for the Northbridge output
• Adaptive body diode conduction time reduction
• Superior noise immunity and transient response
• Output current and voltage telemetry
• Differential remote voltage sensing
• High efficiency across entire load range
• Programmable slew rate
• Programmable VID offset and droop on both outputs
• Programmable switching frequency for both outputs
• Excellent dynamic current balance between phases
• Protection: OCP/WOC, OVP, PGOOD, and thermal monitor
• Small footprint 48 Ld 6x6 QFN package
- Pb-free (RoHS compliant)
Core Performance
100
90
80
70
60
50
40
30
20
10
0
0
V_IN = 8V
V_IN = 12V
V_IN = 19V
V_OUT CORE = 1.1V
5 10 15 20 25 30 35 40 45 50 55
I_OUT (A)
FIGURE 1. EFFICIENCY vs LOAD
1.12
1.10
1.08
1.06
1.04
1.02
V_IN = 12V
V_IN = 8V
1.00
V_IN = 19V
0.98
V_OUT CORE = 1.1V
0.96
0 5 10 15 20 25 30 35 40 45 50 55
I_OUT (A)
FIGURE 2. V_OUT vs LOAD
December 19, 2012
1
FN8322.0
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
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