SMH4046
Preliminary Information 1 (See Last Page)
Hot-Swap, Active DC Output Control (ADOCTM) Power Manager with I2C lnterface
INTRODUCTION
FEATURES & APPLICATIONS
The SMH4046 is an all-inclusive power management
controller that integrates hot swap protection of three
positive-voltage supplies (+12V or less). In addition to
hot swapping three bus voltages, it provides
sequencing and Active DC Output Control (ADOCTM)
of three on-card DC-DC converters as used in blade
servers and Telecom systems. It can also upload
configuration code from the host to on-card FPGAs.
• Full voltage Control for hot-swap applications
- Add-in Card insertion detection
- Platform voltage detection
• Universal FPGA configuration I/O pins
• High Voltage and logic level enable outputs
• Active control (ADOCTM) for three downstream
DC/DC converters with ±0.5% accuracy
• Margining of three DC/DC converters
• Power-up sequencing of all supply voltages
• Power-down sequencing in Forward or Reverse
• UV and OV sensors per channel with
programmable reset and interrupt
All six channels can cascade-sequence during power-
up in any order as set by either hardware or firmware;
and sequence down in forward or reverse order.
ADOCTM control of the three DC/DC converters
maintains their accuracy to within ±0.5% of the set
point using an internal voltage reference. ADOCTM is
also included during “margining” to allow card-by-card
performance evaluation during production with
arbitrary setting within ±10% in any combination.
A full set of monitoring and control features are
included, with user programmability that can be
locked. The SMH4046 uses the I2C bus interface for
programming and FPGA configuration.
• Programmable glitch filter for all channels
• Configuration may be locked
• Auto monitoring of all channels and Ext Temp
• I2CTM serial bus interface
• Programmable slew rate control
• Integrated 2K EEPROM
Applications
• Monitor/Control Distributed and POL Supplies
• Multi-voltage Processors, DSPs, ASICs used in
Telecom or server systems
TYPICAL APPLICATIONS DRAWING
Ejector
Switch
BD_SEL1#
FPGA
FS
+3.3V
5
+5V
+12V
GND
DC/DC #1
VMA
PUPA
TEMP
GND
GND
+5V
TRIMA
TRIM
OE
VOUT
Vout1
Vout2
VIN
VCC5
VMB
DC/DC #2
TRIM
OE
TRIMB
PUPB
VOUT
VIN
VMC
TRIMC
PUPC
DC/DC #3
VOUT
TRIM
OE
•Hot swap
•ADOCTM
GND
GND
Vout3
D
S
VIN
HST_PWR
G
VGATE5
47nF
•Pwr On/Off
•Cascade
•Sequence
•Monitor
CARD_5V
VCC3
HST_RST#
PND2#
Board 5V
PCI_RST#
BD_SEL#
SMH4046
D
S
G
VGATE3
47nF
VGG_CAP
1uF
HEALTHY#
HEALTHY#
CARD_3V
VCC12
Board 3.3V •Margin
•I2C
CARD_V_VLD
47nF
10
S
D
270k
G
DRVREN#
CARD_12V
EXT_TMP
1Vref
A2 SDA
Board 12V
SCL
Pre-
Charge
Circuit
IRQ
PCI Interface ASIC
FAULT
CARD RESET
Figure 1 – Applications Schematic using the SMH4046 Controller to hot swap and actively control the output
levels of three DC/DC Converters while providing power on/off, cascade sequencing and output margining.
Note: This is an applications example only. Some pins, components and values are not shown.
© SUMMIT Microelectronics, Inc. 2004 • 1717 Fox Drive • San Jose CA 95131 • Phone 408 436-9890 • FAX 408 436-9897
The Summit Web Site can be accessed by “right” or “left” mouse clicking on the link: http://www.summitmicro.com/
2082 1.7 08/23/04
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