ISL6532ACR-T [INTERSIL]
ACPI Regulator/Controller for Dual Channel DDR Memory Systems; ACPI稳压器/控制器双通道DDR内存系统型号: | ISL6532ACR-T |
厂家: | Intersil |
描述: | ACPI Regulator/Controller for Dual Channel DDR Memory Systems |
文件: | 总16页 (文件大小:495K) |
中文: | 中文翻译 | 下载: | 下载PDF数据表文档文件 |
ISL6532A
®
Data Sheet
August 2004
FN9099.3
ACPI Regulator/Controller for
Dual Channel DDR Memory Systems
Features
• Generates 3 Regulated Voltages
The ISL6532A provides a complete ACPI compliant power
solution for up to 4 DIMM dual channel DDR/DDR2 Memory
systems. Included are both a synchronous buck controller
- Synchronous Buck PWM Controller with Standby LDO
- 3A Integrated Sink/Source Linear Regulator with
Accurate VDDQ/2 Divider Reference.
and integrated LDO to supply V
with high current during
DDQ
- Glitch-free Transitions During State Changes
- LDO Regulator for 1.5V Video and Core voltage
S0/S1 states and standby current during S3 state. During
S0/S1 state, a fully integrated sink-source regulator
generates an accurate (V
/2) high current V voltage
• ACPI compliant sleep state control
DDQ
TT
without the need for a negative supply. A buffered version of
the V /2 reference is provided as V . An LDO
controller is also integrated for AGP core voltage regulation.
• Integrated V
REF
Buffer
DDQ REF
• PWM Controller Drives Low Cost N-Channel MOSFETs
• 250kHz Constant Frequency Operation
• Tight Output Voltage Regulation
The switching PWM controller drives two N-Channel
MOSFETs in a synchronous-rectified buck converter
topology. The synchronous buck converter uses voltage-
mode control with fast transient response. Both the switching
regulator and standby LDO provide a maximum static
regulation tolerance of ±2% over line, load, and temperature
ranges. The output is user-adjustable by means of external
resistors down to 0.8V.
- All Outputs: ±2% Over Temperature
• 5V or 3.3V Down Conversion
• Fully-Adjustable Outputs with Wide Voltage Range: Down
to 0.8V supports DDR and DDR2 Specifications
• Simple Single-Loop Voltage-Mode PWM Control Design
• Fast PWM Converter Transient Response
• Under and Over-voltage Monitoring on All Outputs
• OCP on the Switching Regulator
Switching memory core output between the PWM regulator
and the standby LDO during state transitions is
accomplished smoothly via the internal ACPI control
circuitry. The NCH signal provides synchronized switching of
a backfeed blocking switch during the transitions eliminating
the need to route 5V Dual to the memory supply.
• Integrated Thermal Shutdown Protection
• QFN Package Option
- QFN Compliant to JEDEC PUB95 MO-220 QFN - Quad
Flat No Leads - Product Outline
An integrated soft-start feature brings all outputs into
regulation in a controlled manner when returning to S0/S1
state from any sleep state. During S0 the PGOOD signal
- QFN Near Chip Scale Package Footprint; Improves
PCB Efficiency, Thinner in Profile
• Pb-free available
indicates V is within spec and operational.
TT
Each output is monitored for under and over-voltage events.
The switching regulator has over current protection. Thermal
shutdown is integrated.
Applications
•
Single and Dual Channel DDR Memory Power Systems in
ACPI compliant PCs
Pinout
ISL6532A (QFN) TOP VIEW
•
Graphics cards - GPU and memory supplies
• ASIC power supplies
• Embedded processor and I/O supplies
• DSP supplies
28
27
26
25
24
23
22
GNDP
5VSBY
GNDQ
GNDQ
VTT
1
2
3
4
5
6
7
21 PGOOD
Ordering Information
20
19
PHASE
DRIVE2
TEMP. RANGE
o
PKG.
DWG. #
PART NUMBER
( C)
PACKAGE
GND
29
18 FB2
ISL6532ACR
0 to 70
0 to 70
28 Ld 6x6 QFN
L28.6x6
L28.6x6
ISL6532ACRZ
(See Note)
28 Ld 6x6 QFN
(Pb-free)
17
16
15
GNDA
COMP
FB
VTT
*Add “-T” suffix to part number for tape and reel packaging.
VDDQ
NOTE: Intersil Pb-free products employ special Pb-free material sets; molding
compounds/die attach materials and 100% matte tin plate termination finish, which
is compatible with both SnPb and Pb-free soldering operations. Intersil Pb-free
products are MSL classified at Pb-free peak reflow temperatures that meet or
exceed the Pb-free requirements of IPC/JEDEC J Std-020B.
8
9
10
11
12
13
14
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
1-888-INTERSIL or 321-724-7143 | Intersil (and design) is a registered trademark of Intersil Americas Inc.
Copyright © Intersil Americas Inc. 2002-2004. All Rights Reserved
1
All other trademarks mentioned are the property of their respective owners.
Block Diagram
P5VSBY
VDDQ S3
S3#
S5#
5VSBY
VOLTAGE
REFERENCE
REGULATOR
+
-
0.800V
0.680V (-15%)
0.920V (+15%)
5V
VDDQ(3)
VTTSNS
12VCC
POR
EA2
+
-
DRIVE2
650Ω OUTPUT
IMPEDANCE
VTT
REG
-
-
+
FB2
+
VTT(2)
GNDQ
S3
UV/OV3
NCH
UV/OV
PWM ENABLE
SLEEP,
SOFT-START,
PGOOD,
AND FAULT
LOGIC
S0
DISABLE
S0/S3
12V
SOFT-START
POR
{
+
-
R
U
+
-
P12V
PWM
EA1
PWM
LOGIC
VREF_IN
UGATE
COMP
OSCILLATOR
250kHz
PHASE
LGATE
+
-
{
UV/OV1
-
+
OC
COMP
20µA
R
L
+
-
GNDA
+
-
UV/OV2
VREF_OUT
PGOOD
FB
OCSET
GNDP
COMP
ISL6532A
Simplified Power System Diagram
12V
5VSBY
5V
ISL6532A
NCH
Q1
SLP_S3
SLP_S5
SLEEP
STATE
LOGIC
V
DDQ
PWM
CONTROLLER
+
Q2
5VSBY/3V3SBY
STANDBY
LDO
V
DDQ
V
V
REF
TT
LINEAR
CONTROLLER
Q3
VTT
REGULATOR
V
AGP
+
+
Typical Application - 5V or 3.3V Input
5VSBY
+12V
+3.3V
C
BP
+5V or +3.3V
R
NCH
PGOOD
S3#
S5#
V
DDQ
SLP_S3
SLP_S5
NCH
Q4
V
REF
+
VREF_OUT
OCSET
C
IN
R
OCSET
VREF_IN
+
UGATE
PHASE
Q1
Q2
V
DDQ
2.5V
L
OUT
+
ISL6532A
VTT
VTT
LGATE
V
C
TT
VDDQ_OUT
VDDQ
VDDQ
VDDQ
+
C
VTT_OUT
V
DDQ
GNDQ
GNDQ
VTTSNS
DRIVE2
Q3
FB
COMP
V
AGP
1.5V
FB2
+
GNDP
GNDA
C
OUT2
3
ISL6532A
Typical Application - Input From 5V Dual
5VSBY
+12V
+3.3V
C
BP
5V Dual
PGOOD
S3#
S5#
V
DDQ
SLP_S3
SLP_S5
NCH
V
REF
+
VREF_OUT
VREF_IN
OCSET
C
IN
R
OCSET
UGATE
PHASE
Q1
Q2
V
DDQ
2.5V
L
OUT
+
ISL6532A
VTT
VTT
LGATE
V
TT
C
VDDQ_OUT
VDDQ
VDDQ
VDDQ
+
C
VTT_OUT
V
DDQ
GNDQ
GNDQ
VTTSNS
DRIVE2
Q3
FB
V
COMP
AGP
1.5V
FB2
+
GNDP
GNDA
C
OUT2
4
ISL6532A
Absolute Maximum Ratings
Thermal Information
o
o
5VSBY, P5VSBY . . . . . . . . . . . . . . . . . . . . . . . . .GND - 0.3V to +7V
P12V . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .GND - 0.3V to +14V
UGATE, LGATE, NCH . . . . . . . . . . . . . . GND - 0.3V to P12V + 0.3V
All other Pins . . . . . . . . . . . . . . . . . . . . GND - 0.3V to 5VCC + 0.3V
ESD Classification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . LEVEL 1
Thermal Resistance (Typical, Notes 1, 2) θJA ( C/W) θJC ( C/W)
QFN Package . . . . . . . . . . . . . . . . . . . 32
Maximum Junction Temperature (Plastic Package) . . . . . . . 150 C
5
o
o
o
Maximum Storage Temperature Range. . . . . . . . . . -65 C to 150 C
Maximum Lead Temperature (Soldering 10s) . . . . . . . . . . . . 300 C
o
(SOIC - Lead Tips Only)
Recommended Operating Conditions
Supply Voltage on 5VSBY . . . . . . . . . . . . . . . . . . . . . . . . +5V ±10%
Supply Voltage on P12V . . . . . . . . . . . . . . . . . . . . . . . . +12V ±10%
Supply Voltage onP5VSBY . . . . . . . . . . . . . . . . . . . . . . . +5V ±10%
o
o
Ambient Temperature Range. . . . . . . . . . . . . . . . . . . . 0 C to 70 C
o
o
Junction Temperature Range. . . . . . . . . . . . . . . . . . . 0 C to 125 C
CAUTION: Stresses above those listed in “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress only rating and operation of the
device at these or any other conditions above those indicated in the operational sections of this specification is not implied.
NOTES:
1. θ is measured in free air with the component mounted on a high effective thermal conductivity test board with “direct attach” features. See
JA
Tech Brief TB379.
2. For θ , the “case temp” location is the center of the exposed metal pad on the package underside.
JC
Electrical Specifications Recommended Operating Conditions, Unless Otherwise Noted. Refer to Block and Simplified Power System
Diagrams and Typical Application Schematics
PARAMETER
5VSBY SUPPLY CURRENT
Nominal Supply Current
SYMBOL
TEST CONDITIONS
MIN
TYP
MAX
UNITS
I
I
S3# & S5# HIGH, UGATE/LGATE Open
3.00
3.50
5.25
-
7.25
4.75
mA
mA
CC_S0
CC_S3
S3# LOW, S5# HIGH, UGATE/LGATE
Open
I
S5# LOW, S3# Dont’t Care,
UGATE/LGATE Open
300
-
800
µA
CC_S5
POWER-ON RESET
Rising 5VSBY POR Threshold
Falling 5VSBY POR Threshold
Rising P12V POR Threshold
Falling P12V POR Threshold
OSCILLATOR AND SOFT-START
PWM Frequency
4.00
3.60
10.0
8.80
-
-
-
-
4.35
3.95
10.5
9.75
V
V
V
V
f
220
-
250
280
-
kHz
V
OSC
Ramp Amplitude
∆V
1.5
OSC
Error Amp Reset Time
VDDQ Soft-Start Interval
REFERENCE VOLTAGE
Reference Voltage
t
Mechanical Off/S5 to S0
Mechanical Off/S5 to S0
6.5
6.5
-
-
9.5
9.5
ms
ms
RESET
t
SS
V
-
0.800
-
-
V
REF
System Accuracy
-2.0
+2.0
%
PWM CONTROLLER ERROR AMPLIFIER
DC Gain
Guaranteed By Design
-
15
-
80
-
-
-
-
dB
Gain-Bandwidth Product
Slew Rate
GBWP
SR
MHz
V/µs
6
STATE LOGIC
S3# Transition Level
V
V
-
-
1.5
1.5
-
-
V
V
S3
S5
S5# Transition Level
5
ISL6532A
Electrical Specifications Recommended Operating Conditions, Unless Otherwise Noted. Refer to Block and Simplified Power System
Diagrams and Typical Application Schematics (Continued)
PARAMETER
PWM CONTROLLER GATE DRIVERS
UGATE and LGATE Source
UGATE and LGATE Sink
NCH BACKFEED CONTROL
NCH Current Sink
SYMBOL
TEST CONDITIONS
MIN
TYP
MAX
UNITS
I
I
-
-
-0.8
0.8
-
-
A
A
GATE
GATE
I
NCH = 0.8V
-
-
6
mA
V
NCH
NCH Trip Level
V
9.0
9.5
10.0
NCH
VDDQ STANDBY LDO
Output Drive Current
P5VSBY = 5.0V
P5VSBY = 3.3V
-
-
-
-
650
550
mA
mA
VTT REGULATOR
Upper Divider Impedance
Lower Divider Impedance
VREF_OUT Buffer Source Current
R
-
-
2.5
2.5
-
-
-
kΩ
kΩ
mA
A
U
R
L
I
-
2
3
VREF_OUT
Maximum V Load Current
TT
I
Periodic load applied with 30% duty cycle
and 10ms period using ISL6532AEVAL1
evaluation board (see Application Note
AN1056)
-3
-
VTT_MAX
LINEAR REGULATOR
DC GAIN
Guaranteed By Design
-
15
-
80
-
-
dB
MHz
V/µs
V
Gain Bandwidth Product
Slew Rate
GBWP
SR
-
6
-
DRIVE2 High Output Voltage
DRIVE2 Low Output Voltage
DRIVE2 High Output Source Current
DRIVE2 Low Output Sink Current
PGOOD
10.0
-
10.2
0.16
-1.4
1.3
-
0.40
V
-.5
.85
-
-
mA
mA
PGOOD Rising Threshold
PGOOD Falling Threshold
PROTECTION
V
V
V
S0
S0
-
-
57.5
45.0
-
-
%
%
VTTSNS/ VDDQ
V
VTTSNS/ VDDQ
OCSET Current Source
VDDQ OV Level
I
17
-
20
115
85
22
-
µA
%
OCSET
V
V
/V
S0
FB REF
VDDQ UV Level
/V
S0
-
-
%
FB REF
/V
Linear Regulator OV Level
Linear Regulator UV Level
Thermal Shutdown Limit
V
V
S0
-
115
85
-
%
FB2 REF
/V
S0
-
-
%
FB2 REF
T
By Design
-
140
-
°C
SD
6
ISL6532A
The FB pin is also monitored for under and over-voltage
events.
Functional Pin Description
5VSBY (Pin 2)
PHASE (Pin 20)
5VSBY is the bias supply of the ISL6532A. It is typically
connected to the 5V standby rail of an ATX power supply.
During S4/S5 sleep states the ISL6532A enters a reduced
Connect this pin to the upper MOSFET’s source. This pin is
used to monitor the voltage drop across the upper MOSFET
for over-current protection.
power mode and draws less than 1mA (I
) from the
CC_S5
5VSBY supply. The supply to 5VSBY should be locally
bypassed using a 0.1µF capacitor.
OCSET (Pin 12)
Connect a resistor (R
) from this pin to the drain of the
OCSET
P12V (Pin 25)
upper MOSFET. R
, an internal 20µA current source
OCSET
(I
), and the upper MOSFET on-resistance (r
)
P12V provides the gate drive to the switching MOSFETs of
OCSET DS(ON)
set the converter over-current (OC) trip point according to
the following equation:
the PWM power stage. The V regulation circuit and the
TT
Linear Driver are also powered by P12V. P12V is not
required except during S0/S1/S2 operation. P12V is typically
connected to the +12V rail of an ATX power supply.
I
xR
OCSET
OCSET
I
= -------------------------------------------------
PEAK
r
DS(ON)
5VSBY (Pin 11)
An over-current trip cycles the soft-start function.
This pin provides the V
state. The regulator is capable of providing standby V
power from either the 5VSBY or 3.3VSBY rail. It is
recommended that the 5VSBY rail be used as the output
current handling capability of the standby LDO is higher than
with the 3.3VSBY rail.
output power during S3 sleep
DDQ
VDDQ (Pins 7, 8, 9)
DDQ
The VDDQ pins should be connected externally together to
the regulated V output. During S0/S1 states, the VDDQ
DDQ
pins serve as inputs to the V regulator and to the V
Reference precision divider. During S3 state, the VDDQ pins
serve as an output from the integrated standby LDO.
TT TT
GND, GNDA, GNDP, GNDQ (Pins 1, 3, 4, 17, 29)
VTT (Pins 5, 6)
The GND terminals of the ISL6532A provide the return path
The VTT pins should be connect externally together. During
for the V LDO, standby LDO and switching MOSFET gate
TT
S0/S1 states, the VTT pins serve as the outputs of the V
TT
drivers. High ground currents are conducted directly through
the exposed paddle of the QFN package which must be
electrically connected to the ground plane through a path as
low in inductance as possible. GNDA is the Analog ground
pin, GNDQ is the return for the VTT regulator and GNDP is
the return for the upper and lower gate drives.
linear regulator. During S3 state, the V regulator is
TT
disabled.
VTTSNS (Pin 10)
VTTSNS is used as the feedback for control of the V linear
TT
regulator. Connect this pin to the V output at the physical
TT
point of desired regulation.
UGATE (Pin 26)
UGATE drives the upper (control) FET of the V
DDQ
synchronous buck switching regulator. UGATE is driven
between GND and P12V.
VREF_OUT (Pin 13)
VREF_OUT is a buffered version of V and also acts as the
TT
reference voltage for the V linear regulator. It is
TT
recommended that a minimum capacitance of 0.1µF is
LGATE (Pin 27)
connected between V
between VREF_OUT and ground for proper operation.
and VREF_OUT and also
DDQ
LGATE drives the lower (synchronous) FET of the V
synchronous buck switching regulator. LGATE is driven
between GND and P12V.
DDQ
VREF_IN (Pin 14)
A capacitor, C , connected between VREF_IN and ground
SS
FB (Pin 15) and COMP (Pin 16)
is required. This capacitor and the parallel combination of
The V
DDQ
switching regulator employs a single voltage
the Upper and Lower Divider Impedance (R ||R ), sets the
U
L
control loop. FB is the negative input to the voltage loop error
amplifier. The positive input of the error amplifier is
connected to a precision 0.8V reference and the output of
time constant for the start up ramp when transitioning from
S3 to S0/S1/S2.
the error amplifier is connected to the COMP pin. The V
output voltage is set by an external resistor divider
DDQ
The minimum value for C can be found through the
SS
following equation:
connected to FB. With a properly selected divider, V
can
DDQ
C
⋅ V
DDQ
VTTOUT
be set to any voltage between the power rail (reduced by
converter losses) and the 0.8V reference. Loop
compensation is achieved by connecting an AC network
across COMP and FB.
------------------------------------------------
>
C
SS
||
10 ⋅ 2A ⋅ R
R
L
U
7
ISL6532A
The calculated capacitance, C , will charge the output
SS
ACPI compliance is realized through the SLP_S3 and
SLP_S5 sleep signals and through monitoring of the 12V
ATX bus.
capacitor bank on the V rail in a controlled manner without
TT
reaching the current limit of the V LDO.
TT
NCH (Pin 22)
Initialization
NCH is an open-drain output that controls the MOSFET
The ISL6532A automatically initializes upon receipt of input
power. Special sequencing of the input supplies is not
necessary. The Power-On Reset (POR) function continually
monitors the input bias supply voltages. The POR monitors
the bias voltage at the 5VSBY and P12V pins. The POR
function initiates soft-start operation after the bias supply
voltages exceed their POR thresholds.
blocking backfeed from V
to the input rail during sleep
DDQ
states. A 2kΩ or larger resistor is to be tied between the 12V
rail and the NCH pin. Until the voltage on the NCH pin
reaches the NCH trip level, the PWM is disabled.
If NCH is not actively utilized, it still must be tied to the 12V
rail through a resistor. For systems using 5V dual as the
input to the switching regulator, a time constant, in the form
of a capacitor, can be added to the NCH pad to delay start of
the PWM switcher until the 5V dual has switched from
5VSBY to 5VATX.
ACPI State Transitions
Cold Start (S4/S5 to S0 Transition)
At the onset of a mechanical start, the ISL6532A receives it’s
bias voltage from the 5V Standby bus (5VSBY). As soon as
the SLP_S3 and SLP_S5 have transitioned HIGH, the
ISL6532A starts an internal counter. Following a cold start or
any subsequent S4/S5 state, state transitions are ignored
until the system enters S0/S1. None of the regulators will
begin the soft start procedure until the 5V Standby bus has
PGOOD (Pin 21)
Power Good is an open-drain logic output that changes to a
logic low if any of the three regulators are out of regulation in
S0/S1/S2 state. PGOOD will always be low in any state other
than S0/S1/S2.
exceeded POR, the 12V bus has exceeded POR and V
SLP_S5# (Pin 24)
NCH
has exceeded the trip level.
This pin accepts the SLP_S5# sleep state signal.
Once all of these conditions are met, the PWM error
amplifier will first be reset by internally shorting the COMP
pin to the FB pin. This reset lasts for 2048 clock cycles,
SLP_S3# (Pin 23)
This pin accepts the SLP_S3# sleep state signal.
which is typically 8.2ms (one clock cycle = 1/f
digital soft start sequence will then begin.
). The
OSC
FB2 (Pin 18)
Connect the output of the external linear regulator to this pin
through a properly sized resistor divider. The voltage at this
pin is regulated to 0.8V. This pin is monitored for under and
over-voltage events.
The PWM error amplifier reference input is clamped to a
level proportional to the soft-start voltage. As the soft-start
voltage slews up, the PWM comparator generates PHASE
pulses of increasing width that charge the output
DRIVE2 (Pin 19)
capacitor(s). The internal VTT LDO will also soft start
through the reference that tracks the output of the PWM
regulator. The reference for the AGP LDO controller will rise
relative to the soft start reference. The soft start lasts for
2048 clock cycles, which is typically 8.2ms. This method
provides a rapid and controlled output voltage rise.
Connect this pin to the gate terminal of an external N-
Channel MOSFET transistor. This pin provides the gate
voltage for the linear regulator pass transistor. It also
provides a means of compensating the error amplifier for
applications requiring the transient response of the linear
regulator to be optimized.
Figure 1 shows the soft start sequence for a typical cold
Functional Description
start. Due to the soft start capacitance, C , on the
VREF_IN pin, the S5 to S0 transition profile of the V rail
TT
will have a more rounded features at the start and end of the
SS
Overview
The ISL6532A provides complete control, drive, protection
and ACPI compliance for a regulator powering DDR memory
systems. It is primarily designed for computer applications
powered from an ATX power supply. A 250kHz Synchronous
Buck Regulator with a precision 0.8V reference provides the
proper Core voltage to the system memory of the computer.
An internal LDO regulator with the ability to both sink and
source current and an externally available buffered reference
soft start whereas the V
profile has distinct starting and
DDQ
ending points to the ramp up.
By directly monitoring 12VATX and the SLP_S3 and SLP_S5
signals the ISL6532A can achieve PGOOD status
significantly faster than other devices that depend on
Latched_Backfeed_Cut for timing.
Active to Sleep (S0 to S3 Transition)
that tracks the V
output by 50% provides the V
DDQ
TT
When SLP_S3 goes LOW with SLP_S5 still HIGH, the
ISL6532A will disable the V linear regulator and the AGP
LDO controller. The V
DDQ
termination voltage. The ISL6532A also features an LDO
regulator for 1.5V AGP Video and Core voltage.
TT
standby regulator will be enabled
8
ISL6532A
should be noted that the soft start profile of the V LDO
TT
output will vary according to the value of the capacitor on the
VREF_IN pin.
S3
S5
12VATX 2V/DIV
5VSBY
1V/DIV
V
S3
DDQ
500mV/DIV
S5
V
AGP
500mV/DIV
12VATX 2V/DIV
V
TT
V
DDQ
500mV/DIV
500mV/DIV
V
AGP
500mV/DIV
PGOOD
5V/DIV
V
TT_FLOAT
V
TT
2048 CLOCK
CYCLES
2048 CLOCK
CYCLES
500mV/DIV
SOFT START ENDS
PGOOD COMPARATOR
ENABLED
SOFT START
INITIATES
12V POR
PGOOD
5V/DIV
FIGURE 1. TYPICAL COLD START
2048 CLOCK
CYCLES
PGOOD COMPARATOR
ENABLED
and the V
switching regulator will be disabled. NCH is
DDQ
12V POR
pulled low to disable the backfeed blocking MOSFET.
PGOOD will also transition LOW. When V is disabled, the
FIGURE 2. TYPICAL S3 to S0 STATE TRANSITION
TT
internal reference for the V regulator is internally shorted
TT
to the V rail. This allows the V rail to float. When
Active to Shutdown (S0 to S5 Transition)
TT
TT
floating, the voltage on the V rail will depend on the
leakage characteristics of the memory and MCH I/O pins. It
is important to note that the V rail may not bleed down to 0V.
TT
TT
When the system transitions from active, S0, state to
shutdown, S4/S5, state, the ISL6532A IC disables all
regulators and forces the PGOOD pin and the NCH pin
LOW.
The V
DDQ
rail will be supported in the S3 state through the
LDO. When S3 transitions LOW, the Standby
standby V
DDQ
V
Over Current Protection (S0 State)
DDQ
regulator is immediately enabled. The switching regulator is
disabled synchronous to the switching waveform. The shut
off time will range between 4 and 8us. The standby LDO is
capable of supporting up to 650mA of load with P5VSBY tied
to the 5V Standby Rail. The standby LDO may receive input
from either the 3.3V Standby rail or the 5V Standby rail
through the P5VSBY pin. It is recommended that the 5V
Standby rail be used as the current delivery capability of the
LDO is greater.
The over-current function protects the switching converter
from a shorted output by using the upper MOSFET on-
resistance, r
, to monitor the current. This method
DS(ON)
enhances the converter’s efficiency and reduces cost by
eliminating a current sensing resistor.
The over-current function cycles the soft-start function in a
hiccup mode to provide fault protection. A resistor (R
)
OCSET
programs the over-current trip level (see Typical Application
diagrams on pages 3 and 4). An internal 20µA (typical)
Sleep to Active (S3 to S0 Transition)
current sink develops a voltage across R
that is
OCSET
When SLP_S3 transitions from LOW to HIGH with SLP_S5
held HIGH and after the 12V rail exceeds POR, the
referenced to the converter input voltage. When the voltage
across the upper MOSFET (also referenced to the converter
ISL6532A will enable the V
switching regulator, disable
DDQ
standby regulator, enable the V LDO and force
input voltage) exceeds the voltage across R
, the over-
OCSET
the V
DDQ
TT
current function initiates a soft-start sequence. The initiation
the NCH pin to a high impedance state turning on the
blocking MOSFET. The AGP LDO goes through a 2048 clock
cycle soft-start. The internal short between the V
reference and the V rail is released. Upon release of the
TT
short, the capacitor on VREF_IN is then charged up through
the internal resistor divider network. The V output will
of soft start will affect all regulators. The V regulator is
TT
directly affected as it receives it’s reference from V
. The
DDQ
TT
AGP LDO will also be soft started, and as such, the AGP
LDO voltage will be disabled while the V
disabled.
regulator is
DDQ
TT
Figure 3 illustrates the protection feature responding to an
over current event. At time T0, an over current condition is
sensed across the upper MOSFET. As a result, the regulator
is quickly shutdown and the internal soft-start function
begins producing soft-start ramps. The delay interval seen
follow this capacitor charge up, and acting as the S3 to S0
transition soft start for the V rail. The PGOOD comparator
TT
is enabled only after 2048 clock cycles, or typically 8.2ms,
have passed following the S3 transition to a HIGH state.
Figure 2 illustrates a typical state transition from S3 to S0. It
9
ISL6532A
by the output is equivalent to three soft-start cycles. The
fourth internal soft-start cycle initiates a normal soft-start
ramp of the output, at time T1. The output is brought back
into regulation by time T2, as long as the over current event
has cleared.
For an equation for the ripple current see the section under
component guidelines titled ‘Output Inductor Selection’.
A small ceramic capacitor should be placed in parallel with
R
to smooth the voltage across
R
in the
OCSET
OCSET
presence of switching noise on the input voltage.
Had the cause of the over current still been present after the
delay interval, the over current condition would be sensed
and the regulator would be shut down again for another
delay interval of three soft start cycles. The resulting hiccup
mode style of protection would continue to repeat indefinitely.
Over/Under Voltage Protection
All three regulators are protected from faults through internal
Over/Under voltage detection circuitry. If the any rail falls
below 85% of the targeted voltage, then an undervoltage
event is tripped. An under voltage will disable all three
regulators for a period of 3 soft-start cycles, after which a
normal soft-start is initiated. If the output is still under 85% of
target, the regulators will continue to be disabled and soft-
started in a hiccup mode until the fault is cleared. This
protection feature works much the same as the VDDQ PWM
over current protection works. See Figure 3.
V
DDQ
V
AGP
If the any rail exceeds 115% of the targeted voltage, then all
three outputs are immediately disabled. The ISL6532A will
not re-enable the outputs until either the bias voltage is
toggled in order to initiate a POR or the S5 signal is forced
LOW and then back to HIGH.
V
TT
500mV/DIV
Thermal Protection (S0/S3 State)
INTERNAL SOFT-START FUNCTION
DELAY INTERVAL
If the ISL6532A IC junction temperature reaches a nominal
o
temperature of 140 C, all regulators will be disabled. The
ISL6532A will not re-enable the outputs until the junction
o
temperature drops below 110 C and either the bias voltage
is toggled in order to initiate a POR or the SLP_S5 signal is
forced LOW and then back to HIGH.
T0
T1
T2
Shoot-Through Protection
TIME
A shoot-through condition occurs when both the upper and
lower MOSFETs are turned on simultaneously, effectively
shorting the input voltage to ground. To protect from a shoot-
through condition, the ISL6532A incorporates specialized
circuitry which insures that complementary MOSFETs are
not ON simultaneously.
FIGURE 3. V
V
OVER CURRENT PROTECTION AND
DDQ
/V
LDO UNDER VOLTAGE PROTECTION
TT AGP
RESPONSES
The over-current function will trip at a peak inductor current
(I
determined by:
PEAK)
The adaptive shoot-through protection utilized by the V
DDQ
I
x R
OCSET
OCSET
I
= ----------------------------------------------------
PEAK
regulator looks at the lower gate drive pin, LGATE, and the
upper gate drive pin, UGATE, to determine whether a
MOSFET is ON or OFF. If the voltage from UGATE or from
LGATE to GND is less than 0.8V, then the respective
MOSFET is defined as being OFF and the other MOSFET is
r
DS(ON)
where I
is the internal OCSET current source (20µA
OCSET
typical). The OC trip point varies mainly due to the MOSFET
variations. To avoid over-current tripping in the
normal operating load range, find the R
the equation above with:
r
DS(ON)
allowed to turned ON. This method allows the V
regulator to both source and sink current.
DDQ
resistor from
OCSET
Since the voltage of the MOSFET gates are being measured
to determine the state of the MOSFET, the designer is
encouraged to consider the repercussions of introducing
external components between the gate drivers and their
respective MOSFET gates before actually implementing
such measures. Doing so may interfere with the shoot-
through protection.
1. The maximum r
temperature.
at the highest junction
DS(ON)
2. The minimum I
from the specification table.
OCSET
3. Determine I
for:
PEAK
(∆I)
----------
I
> I
+
,where ∆I is
PEAK
OUT(MAX)
2
the output inductor ripple current.
10
ISL6532A
12V
ATX
Application Guidelines
P12V
C
BP
Layout Considerations
GNDP
V
IN_DDR
Layout is very important in high frequency switching
ISL6532A
converter design. With power devices switching efficiently at
250kHz, the resulting current transitions from one device to
another cause voltage spikes across the interconnecting
impedances and parasitic circuit elements. These voltage
spikes can degrade efficiency, radiate noise into the circuit,
and lead to device over-voltage stress. Careful component
layout and printed circuit board design minimizes these
voltage spikes.
NCH
5VSBY
P5VSBY
5VSBY
C
IN
C
BP
GNDP
L
UGATE
PHASE
OUT
Q
1
V
DDQ
As an example, consider the turn-off transition of the control
MOSFET. Prior to turn-off, the MOSFET is carrying the full
load current. During turn-off, current stops flowing in the
MOSFET and is picked up by the lower MOSFET. Any
parasitic inductance in the switched current path generates a
large voltage spike during the switching interval. Careful
component selection, tight layout of the critical components,
and short, wide traces minimizes the magnitude of voltage
spikes.
C
OUT1
LGATE
COMP
Q
2
C
2
C
1
R
2
R
1
FB
C
R
3
3
R
4
VDDQ(3)
VTT(2)
V
DDQ
There are two sets of critical components in the ISL6532A
switching converter. The switching components are the most
critical because they switch large amounts of energy, and
therefore tend to generate large amounts of noise. Next are
the small signal components which connect to sensitive
nodes or supply critical bypass current and signal coupling.
V
TT
C
OUT2
V
IN_AGP
Q
3
DRIVE2
FB2
R
V
AGP
5
A multi-layer printed circuit board is recommended. Figure 4
shows the connections of the critical components in the
GND PAD
R
6
C
OUT3
converter. Note that capacitors C and C
could each
IN OUT
represent numerous physical capacitors. Dedicate one solid
layer, usually a middle layer of the PC board, for a ground
plane and make all critical component ground connections
with vias to this layer. Dedicate another solid layer as a
power plane and break this plane into smaller islands of
common voltage levels. Keep the metal runs from the
PHASE terminals to the output inductor short. The power
plane should support the input power and output power
nodes. Use copper filled polygons on the top and bottom
circuit layers for the phase nodes. Use the remaining printed
circuit layers for small signal wiring. The wiring traces from
the GATE pins to the MOSFET gates should be kept short
and wide enough to easily handle the 1A of drive current.
KEY
ISLAND ON POWER PLANE LAYER
ISLAND ON CIRCUIT PLANE LAYER
VIA CONNECTION TO GROUND PLANE
FIGURE 4. PRINTED CIRCUIT BOARD POWER PLANES
AND ISLANDS
possible. Position the output inductor and output capacitors
between the upper and lower MOSFETs and the load.
The critical small signal components include any bypass
capacitors, feedback components, and compensation
components. Place the PWM converter compensation
components close to the FB and COMP pins. The feedback
resistors should be located as close as possible to the FB
pin with vias tied straight to the ground plane as required.
In order to dissipate heat generated by the internal V LDO,
TT
the ground pad, pin 29, should be connected to the internal
ground plane through at least four vias. This allows the heat
to move away from the IC and also ties the pad to the ground
plane through a low impedance path.
Feedback Compensation - PWM Buck Converter
Figure 5 highlights the voltage-mode control loop for a
synchronous-rectified buck converter. The output voltage
The switching components should be placed close to the
ISL6532A first. Minimize the length of the connections
(V
) is regulated to the Reference voltage level. The error
OUT
between the input capacitors, C , and the power switches
IN
amplifier output (V ) is compared with the oscillator (OSC)
E/A
by placing them nearby. Position both the ceramic and bulk
input capacitors as close to the upper MOSFET drain as
triangular wave to provide a pulse-width modulated (PWM)
wave with an amplitude of V at the PHASE node.
IN
11
ISL6532A
ND
The PWM wave is smoothed by the output filter (L and C ).
5. Place 2
Pole at Half the Switching Frequency.
O
O
V
6. Check Gain against Error Amplifier’s Open-Loop Gain.
7. Estimate Phase Margin - Repeat if Necessary.
DRIVER
IN
OSC
PWM
L
O
COMPARATOR
V
DDQ
Compensation Break Frequency Equations
-
DRIVER
PHASE
+
∆V
OSC
C
O
1
1
F
F
= -----------------------------------
F
F
= --------------------------------------------------------
Z1
P1
2π x R x C
C
x C
2
2
2
1
ESR
(PARASITIC)
---------------------
2π x R
x
2
C
+ C
1
2
Z
FB
1
1
V
= ------------------------------------------------------
= -----------------------------------
E/A
Z2
P2
2π x (R + R ) x C
2π x R x C
1
3
3
3
3
Z
-
IN
+
REFERENCE
Figure 6 shows an asymptotic plot of the DC-DC converter’s
gain vs. frequency. The actual Modulator Gain has a high
gain peak due to the high Q factor of the output filter and is
not shown in Figure 6. Using the above guidelines should
give a Compensation Gain similar to the curve plotted. The
open loop error amplifier gain bounds the compensation
ERROR
AMP
DETAILED COMPENSATION COMPONENTS
Z
FB
V
DDQ
C
1
Z
IN
C
C
R
R
3
2
3
2
gain. Check the compensation gain at F with the
P2
capabilities of the error amplifier. The Closed Loop Gain is
constructed on the graph of Figure 6 by adding the
Modulator Gain (in dB) to the Compensation Gain (in dB).
This is equivalent to multiplying the modulator transfer
function to the compensation transfer function and plotting
the gain.
R
1
COMP
FB
-
+
R
4
ISL6532A
REFERENCE
The compensation gain uses external impedance networks
R
1
V
= 0.8 × 1 + ------
Z
and Z to provide a stable, high bandwidth (BW) overall
DDQ
FB
IN
R
4
loop. A stable control loop has a gain crossing with
-20dB/decade slope and a phase margin greater than 45
degrees. Include worst case component variations when
determining phase margin.
FIGURE 5. VOLTAGE-MODE BUCK CONVERTER
COMPENSATION DESIGN AND OUTPUT
VOLTAGE SELECTION
The modulator transfer function is the small-signal transfer
function of V /V . This function is dominated by a DC
OUT E/A
Gain and the output filter (L and C ), with a double pole
100
F
F
P1
F
F
P2
Z2
Z1
O
O
break frequency at F and a zero at F
the modulator is simply the input voltage (V ) divided by the
. The DC Gain of
80
60
40
20
0
LC ESR
OPEN LOOP
ERROR AMP GAIN
IN
peak-to-peak oscillator voltage ∆V
OSC
.
20LOG
(R /R )
Modulator Break Frequency Equations
2
1
20LOG
1
1
(V /∆V
)
F
= ------------------------------------------
F
= -------------------------------------------
IN OSC
LC
ESR
2π x ESR x C
2π x
L
x C
O O
O
COMPENSATION
GAIN
MODULATOR
GAIN
-20
-40
-60
The compensation network consists of the error amplifier
(internal to the ISL6532A) and the impedance networks Z
CLOSED LOOP
GAIN
IN
F
LC
F
and Z . The goal of the compensation network is to provide
ESR
100K
FREQUENCY (Hz)
FB
10
100
1K
10K
1M
10M
a closed loop transfer function with the highest 0dB crossing
frequency (f
) and adequate phase margin. Phase margin
is the difference between the closed loop phase at f and
0dB
FIGURE 6. ASYMPTOTIC BODE PLOT OF CONVERTER GAIN
0dB
180 degrees. The equations below relate the compensation
Feedback Compensation - AGP LDO Controller
network’s poles, zeros and gain to the components (R , R ,
1
2
R , C , C , and C ) in Figure 5. Use these guidelines for
locating the poles and zeros of the compensation network:
Figure 7 shows the AGP LDO power and control stage. This
LDO, which uses a MOSFET as the linear pass element,
requires feedback compensation to insure stability of the
system. The LDO requires compensation because of the
output impedance of the error amplifier.
3
1
2
3
1. Pick Gain (R /R ) for desired converter bandwidth.
2
1
ST
2. Place 1 Zero Below Filter’s Double Pole (~75% F ).
LC
ND
3. Place 2
Zero at Filter’s Double Pole.
ST
4. Place 1 Pole at the ESR Zero.
12
ISL6532A
Component Selection Guidelines
ISL6532A
V
DDQ
Output Capacitor Selection - PWM Buck Converter
0.8V
REFERENCE
An output capacitor is required to filter the inductor current
and supply the load transient current. The filtering
requirements are a function of the switching frequency and
the ripple current. The load transient requirements are a
function of the slew rate (di/dt) and the magnitude of the
transient load current. These requirements are generally met
with a mix of capacitors and careful layout.
650Ω
DRIVE2
+
-
OUTPUT
IMPEDANCE
V
C
R
AGP
25
10
FB2
R
8
R
9
DDR memory systems are capable of producing transient
load rates above 1A/ns. High frequency capacitors initially
supply the transient and slow the current load rate seen by
the bulk capacitors. The bulk filter capacitor values are
generally determined by the ESR (Effective Series
Resistance) and voltage rating requirements rather than
actual capacitance requirements.
ESR
OUT
R
LOAD
+
R
C
8
V
= 0.8 × 1 + ------
AGP
R
9
FIGURE 7. COMPENSATION AND OUTPUT VOLTAGE
SELECTION OF THE LINEAR
To properly compensate the LDO system, a 100kΩ 1%
High frequency decoupling capacitors should be placed as
close to the power pins of the load as physically possible. Be
careful not to add inductance in the circuit board wiring that
could cancel the usefulness of these low inductance
components. Consult with the manufacturer of the load on
specific decoupling requirements.
resistor and a 680pF X5R ceramic capacitor, represented as
R10 and C25 in Figure 7, are used. This compensation will
insure a stable system with any MOSFET given the following
conditions:
τ = C
⋅ ESR > 10µs
OUT
R
= R = 249Ω
8
FB
Use only specialized low-ESR capacitors intended for
switching-regulator applications for the bulk capacitors. The
bulk capacitor’s ESR will determine the output ripple voltage
and the initial voltage drop after a high slew-rate transient.
An aluminum electrolytic capacitor’s ESR value is related to
the case size with lower ESR available in larger case sizes.
However, the Equivalent Series Inductance (ESL) of these
capacitors increases with case size and can reduce the
usefulness of the capacitor to high slew-rate transient
loading. Unfortunately, ESL is not a specified parameter.
Work with your capacitor supplier and measure the
capacitor’s impedance with frequency to select a suitable
component. In most cases, multiple electrolytic capacitors of
small case size perform better than a single large case
capacitor.
Maximum bandwidth will be realized at full load while
minimum bandwidth will be realized at no load. Bandwidth at
no load will be maximized as τ becomes closer to 10µs.
Output Voltage Selection
The output voltage of the V
PWM converter can be
DDQ
programmed to any level between V and the internal
IN
reference, 0.8V. An external resistor divider is used to scale
the output voltage relative to the reference voltage and feed
it back to the inverting input of the error amplifier, see
Figure 5. However, since the value of R1 affects the values of
the rest of the compensation components, it is advisable to
keep its value less than 5kΩ. Depending on the value chosen
for R1, R4 can be calculated based on the following equation:
R1 × 0.8V
R4 = -----------------------------------
V
- 0.8V
Output Capacitor Selection - LDO Regulators
DDQ
The output capacitors used in LDO regulators are used to
provide dynamic load current. The amount of capacitance
and type of capacitor should be chosen with this criteria in
mind.
If the output voltage desired is 0.8V, simply route V
to the FB pin through R1, but do not populate R4.
back
DDQ
The output voltage for the internal V linear regulator is set
TT
internal to the ISL6532A to track the V
voltage by 50%.
DDQ
Output Inductor Selection
There is no need for external programming resistors.
The output inductor is selected to meet the output voltage
ripple requirements and minimize the converter’s response
time to the load transient. The inductor value determines the
converter’s ripple current and the ripple voltage is a function
of the ripple current. The ripple voltage and current are
approximated by the following equations:
As with the V PWM regulator, the AGP linear regulator
DDQ
output voltage is set by means of an external resistor divider
as shown in Figure 7. For stability concerns described
earlier, the recommended value of the feedback resistor, R8,
is 249Ω. The voltage programming resistor, R9 can be
calculated based on the following equation:
V
- V
OUT
V
OUT
IN
Fs x L
R
× 0.8V
∆V = ∆I x ESR
OUT
∆I =
x
8
R
= ----------------------------------
V
IN
9
V
- 0.8V
AGP
13
ISL6532A
Increasing the value of inductance reduces the ripple current
and voltage. However, the large inductance values reduce
the converter’s response time to a load transient.
For a through hole design, several electrolytic capacitors
may be needed. For surface mount designs, solid tantalum
capacitors can be used, but caution must be exercised with
regard to the capacitor surge current rating. These
capacitors must be capable of handling the surge-current at
power-up. Some capacitor series available from reputable
manufacturers are surge current tested.
One of the parameters limiting the converter’s response to a
load transient is the time required to change the inductor
current. Given a sufficiently fast control loop design, the
ISL6532A will provide either 0% or 100% duty cycle in
response to a load transient. The response time is the time
required to slew the inductor current from an initial current
value to the transient current level. During this interval the
difference between the inductor current and the transient
current level must be supplied by the output capacitor.
Minimizing the response time can minimize the output
capacitance required.
MOSFET Selection - PWM Buck Converter
The ISL6532A requires 2 N-Channel power MOSFETs for
switching power and a third MOSFET to block backfeed from
V
to the Input in S3 Mode. These should be selected
DDQ
based upon r
, gate supply requirements, and thermal
DS(ON)
management requirements.
In high-current applications, the MOSFET power dissipation,
package selection and heatsink are the dominant design
factors. The power dissipation includes two loss
The response time to a transient is different for the
application of load and the removal of load. The following
equations give the approximate response time interval for
application and removal of a transient load:
components; conduction loss and switching loss. The
conduction losses are the largest component of power
dissipation for both the upper and the lower MOSFETs.
These losses are distributed between the two MOSFETs
according to duty factor. The switching losses seen when
sourcing current will be different from the switching losses
seen when sinking current. When sourcing current, the
upper MOSFET realizes most of the switching losses. The
lower switch realizes most of the switching losses when the
converter is sinking current (see the equations below).
These equations assume linear voltage-current transitions
and do not adequately model power loss due the reverse-
recovery of the upper and lower MOSFET’s body diode. The
gate-charge losses are dissipated in part by the ISL6532A
and do not significantly heat the MOSFETs. However, large
L x I
L x I
TRAN
TRAN
OUT
t
=
t
=
FALL
RISE
V
- V
V
OUT
IN
where: I
is the transient load current step, t
is the
TRAN
RISE
is the
response time to the application of load, and t
FALL
response time to the removal of load. The worst case
response time can be either at the application or removal of
load. Be sure to check both of these equations at the
minimum and maximum output levels for the worst case
response time.
Input Capacitor Selection - PWM Buck Converter
Use a mix of input bypass capacitors to control the voltage
overshoot across the MOSFETs. Use small ceramic
capacitors for high frequency decoupling and bulk capacitors
to supply the current needed each time the upper MOSFET
turns on. Place the small ceramic capacitors physically close
to the MOSFETs and between the drain of upper MOSFET
and the source of lower MOSFET.
gate-charge increases the switching interval, t
which
SW
increases the MOSFET switching losses. Ensure that both
MOSFETs are within their maximum junction temperature at
high ambient temperature by calculating the temperature
rise according to package thermal-resistance specifications.
A separate heatsink may be necessary depending upon
MOSFET power, package type, ambient temperature and air
flow.
The important parameters for the bulk input capacitance are
the voltage rating and the RMS current rating. For reliable
operation, select bulk capacitors with voltage and current
ratings above the maximum input voltage and largest RMS
current required by the circuit. Their voltage rating should be
at least 1.25 times greater than the maximum input voltage,
while a voltage rating of 1.5 times is a conservative
guideline. For most cases, the RMS current rating
Approximate Losses while Sourcing current
2
1
--
P
= Io × r
× D + ⋅ Io × V × t
× f
SW
UPPER
LOWER
DS(ON)
IN
2
s
2
P
= Io x r
x (1 - D)
DS(ON)
Approximate Losses while Sinking current
2
P
= Io x r
x D
UPPER
DS(ON)
requirement for the input capacitor of a buck regulator is
approximately 1/2 the DC load current.
2
1
--
P
= Io × r
× (1 - D) + ⋅ Io × V × t
× f
SW s
LOWER
DS(ON)
IN
2
Where: D is the duty cycle = V
OUT
/ V ,
IN
is the combined switch ON and OFF time, and
The maximum RMS current required by the regulator may be
closely approximated through the following equation:
t
SW
f is the switching frequency.
s
2
VOUT
-------------
VIN
VIN - VOUT VOUT
2
1
12
------
----------------------------- -------------
IRMS
=
× IOUT
+
×
×
VIN
L × fs
MAX
MAX
14
ISL6532A
ISL6532A Application Circuit
MOSFET Selection - AGP LDO
The main criteria for selection of the linear regulator pass
transistor is package selection for efficient removal of heat.
Select a package and heatsink that maintains the junction
temperature below the rating with a maximum expected
ambient temperature.
Figure 8 shows an application circuit utilizing the ISL6532A.
Detailed information on the circuit, including a complete Bill-
of-Materials and circuit board description, can be found in
Application Note AN1056.
The power dissipated in the linear regulator is:
P
≅ I × (V - V
)
OUT
LINEAR
O
IN
where I is the maximum output current and V
O
is the
OUT
nominal output voltage of the linear regulator.
VCC5
5VSBY
VCC12
R
1
+3.3V
4.99kΩ
C
17,18
1µF
Q
5
R
C
2
16
1µF
10.0kΩ
L
PGOOD
PGOOD
S5#
1
NCH
2.1µH
V
DDQ
SLP_S5
SLP_S3
C
1000pF
22
S3#
C
26
0.1µF
V
REF
+
C
C
1-3
4,5
1µF
OCSET
VREF_OUT
VREF_IN
2200µF
R
7
8.87kΩ
C
0.1µF
27
V
UGATE
PHASE
Q
DDQ
1,3
C
19
0.47µF
2.5V 15A
MAX
V
DDQ
L
2
C
+
6-8
+
ISL6532A
2.1µH
V
C
TT
1.25V
20
220µF
1800µF
VTT
VTT
C
22µF
LGATE
9-12
Q
2,4
VDDQ
VDDQ
VDDQ
+
C
220µF
21
V
DDQ
VTTSNS
DRIVE2
R
4
1.74kΩ
GNDQ
GNDQ
Q
4
R
100kΩ
10
FB
V
AGP
1.5V
C
C
R
5
22.6Ω
COMP
680pF
25
13
56nF
FB2
C
15
R
1000pF
8
+
R
9
C
220µF
23
249Ω
C
287Ω
24
1µF
C
6.8nF
R
14
3
19.1kΩ
R
6
825Ω
FIGURE 8. DDR SDRAM AND AGP VOLTAGE REGULATOR USING THE ISL6532A
15
ISL6532A
Quad Flat No-Lead Plastic Package (QFN)
Micro Lead Frame Plastic Package (MLFP)
L28.6x6
28 LEAD QUAD FLAT NO-LEAD PLASTIC PACKAGE
(COMPLIANT TO JEDEC MO-220VJJC ISSUE C)
MILLIMETERS
SYMBOL
MIN
NOMINAL
MAX
1.00
0.05
1.00
NOTES
A
A1
A2
A3
b
0.80
0.90
-
-
-
-
-
-
9
0.20 REF
9
0.23
3.95
3.95
0.28
0.35
4.25
4.25
5, 8
D
6.00 BSC
-
D1
D2
E
5.75 BSC
9
4.10
7, 8
6.00 BSC
-
E1
E2
e
5.75 BSC
9
4.10
7, 8
0.65 BSC
-
k
0.25
0.35
-
-
-
-
L
0.60
0.75
0.15
8
L1
N
-
28
7
7
-
10
2
Nd
Ne
P
3
3
-
-
0.60
12
9
θ
-
9
Rev. 1 10/02
NOTES:
1. Dimensioning and tolerancing conform to ASME Y14.5-1994.
2. N is the number of terminals.
3. Nd and Ne refer to the number of terminals on each D and E.
4. All dimensions are in millimeters. Angles are in degrees.
5. Dimension b applies to the metallized terminal and is measured
between 0.15mm and 0.30mm from the terminal tip.
6. The configuration of the pin #1 identifier is optional, but must be
located within the zone indicated. The pin #1 identifier may be
either a mold or mark feature.
7. Dimensions D2 and E2 are for the exposed pads which provide
improved electrical and thermal performance.
8. Nominal dimensionsare provided toassistwith PCBLandPattern
Design efforts, see Intersil Technical Brief TB389.
9. Features and dimensions A2, A3, D1, E1, P & θ are present when
Anvil singulation method is used and not present for saw
singulation.
10. Depending on the method of lead termination at the edge of the
package, a maximum 0.15mm pull back (L1) maybe present. L
minus L1 to be equal to or greater than 0.3mm.
All Intersil U.S. products are manufactured, assembled and tested utilizing ISO9000 quality systems.
Intersil Corporation’s quality certifications can be viewed at www.intersil.com/design/quality
Intersil products are sold by description only. Intersil Corporation reserves the right to make changes in circuit design, software and/or specifications at any time without
notice. Accordingly, the reader is cautioned to verify that data sheets are current before placing orders. Information furnished by Intersil is believed to be accurate and
reliable. However, no responsibility is assumed by Intersil or its subsidiaries for its use; nor for any infringements of patents or other rights of third parties which may result
from its use. No license is granted by implication or otherwise under any patent or patent rights of Intersil or its subsidiaries.
For information regarding Intersil Corporation and its products, see www.intersil.com
16
相关型号:
ISL6532ACR-TK
3A SWITCHING CONTROLLER, 280kHz SWITCHING FREQ-MAX, PQCC28, 6 X 6 MM, PLASTIC, MO-220VJJC, MLFP, QFN-28
RENESAS
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