19-3721; Rev 0; 5/05
KIT
ATION
EVALU
BLE
AVAILA
Dual-Phase, Quick-PWM Controller for AMD
Mobile Turion 64 CPU Core Power Supplies
General Description
The MAX8760 is a dual-phase, Quick-PWM™, step-
down controller for 6-bit VID AMD Mobile Turion™ 64
CPU core supplies. Dual-phase operation reduces input
ripple current requirements and output voltage ripple
while easing component selection and layout difficulties.
The Quick-PWM control scheme provides instantaneous
response to fast-load current steps. The MAX8760
includes active voltage positioning with adjustable gain
and offset, reducing power dissipation and bulk output
capacitance requirements.
The MAX8760 is intended for two different notebook CPU
core applications: stepping down the battery directly or
stepping down the 5V system supply to create the core
voltage. The single-stage conversion method allows this
device to directly step down high-voltage batteries for the
highest possible efficiency. Alternatively, two-stage con-
version (stepping down the 5V system supply instead of
the battery) at a higher switching frequency provides the
minimum possible physical size.
The MAX8760 complies with AMD’s desktop and mobile
CPU specifications. The switching regulator features soft-
start and power-up sequencing, and soft-shutdown. The
MAX8760 also features independent four-level logic inputs
for setting the suspend voltage (S0, S1).
The MAX8760 includes output undervoltage protection,
thermal protection, and voltage regulator power-OK
(VROK) output. When any of these protection features
detect a fault, the controller shuts down.
The MAX8760 is available in a low-profile, 40-pin 6mm x
6mm thin QFN package. For other CPU platforms, refer to
the pin-to-pin compatible MAX1544, MAX1519/MAX1545,
and MAX1532/MAX1546/MAX1547 data sheets.
♦
Dual-Phase, Quick-PWM Controller
♦
±0.75% V
OUT
Accuracy Over Line, Load, and
Temperature (1.3V)
♦
Active Voltage Positioning with Adjustable Gain
and Offset
♦
6-Bit On-Board DAC: 0.375V to 1.55V Output
Adjust Range
♦
Selectable 100kHz/200kHz/300kHz/550kHz
Switching Frequency
♦
4V to 28V Battery Input Voltage Range
♦
Adjustable Slew-Rate Control
♦
Drives Large Synchronous Rectifier MOSFETs
♦
Undervoltage and Thermal-Fault Protection
♦
Power Sequencing and Timing
♦
Selectable Suspend Voltage
♦
Soft-Start and Soft-Shutdown
♦
Selectable Single- or Dual-Phase Pulse Skipping
Features
MAX8760
Ordering Information
PART
MAX8760ETL
TEMP RANGE
-40°C to +100°C
PIN-PACKAGE
40 Thin QFN 6mm x 6mm
40 Thin QFN 6mm x 6mm
MAX8760ETL+ -40°C to +100°C
+Denotes
lead-free package.
Pin Configuration
DLM
DHM
V
DD
TOP VIEW
LXM
BSTM
VROK
D0
D1
D2
D3
Applications
6-Bit VID AMD Mobile Turion 64 CPU
Multiphase CPU Core Supply
Voltage-Positioned Step-Down Converters
Servers/Desktop Computers
PGND
DLS
DHS
LXS
BSTS
V+
CMP
CMN
CSN
CSP
31
32
33
34
35
36
37
38
39
40
30 29 28 27 26 25 24 23 22 21
20
19
18
17
16
D4
D5
SKIP
OAIN+
OAIN-
FB
CCI
GNDS
CCV
GND
MAX8760
15
14
13
12
11
1
TIME
2
3
4
5
6
7
8
9 10
SHDN
OFS
S0
S1
Quick-PWM is a trademark of Maxim Integrated Products, Inc.
Turion is a trademark of AMD.
THIN QFN
1
________________________________________________________________
Maxim Integrated Products
For pricing delivery, and ordering information please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
REF
ILIM
V
CC
TON
SUS
Dual-Phase, Quick-PWM Controller for AMD
Mobile Turion 64 CPU Core Power Supplies
MAX8760
ABSOLUTE MAXIMUM RATINGS
V+ to GND ..............................................................-0.3V to +30V
V
CC
to GND ..............................................................-0.3V to +6V
V
DD
to PGND............................................................-0.3V to +6V
SKIP,
SUS, D0–D5 to GND.......................................-0.3V to +6V
ILIM, FB, OFS, CCV, CCI, REF, OAIN+,
OAIN- to GND.........................................-0.3V to (V
CC
+ 0.3V)
CMP, CSP, CMN, CSN, GNDS to GND ......-0.3V to (V
CC
+ 0.3V)
TON, TIME, VROK, S0–S1 to GND..............-0.3V to (V
CC
+ 0.3V)
SHDN
to GND (Note 1)...........................................-0.3V to +18V
DLM, DLS to PGND ....................................-0.3V to (V
DD
+ 0.3V)
BSTM, BSTS to GND ..............................................-0.3V to +36V
DHM to LXM ...........................................-0.3V to (V
BSTM
+ 0.3V)
LXM to BSTM............................................................-6V to +0.3V
DHS to LXS..............................................-0.3V to (V
BSTS
+ 0.3V)
LXS to BSTS .............................................................-6V to +0.3V
GND to PGND .......................................................-0.3V to +0.3V
REF Short-Circuit Duration .........................................Continuous
Continuous Power Dissipation (T
A
= +70°C)
40-Pin 6mm
✕
6mm Thin QFN
(derate 23.2mW/°C above +70°C) ...............................1.860W
Operating Temperature Range .........................-40°C to +100°C
Junction Temperature ......................................................+150°C
Storage Temperature Range .............................-65°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
Note 1:
SHDN
may be forced to 12V for the purpose of debugging prototype boards using the no-fault test mode, which disables
fault protection and overlapping operation.
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
ELECTRICAL CHARACTERISTICS
(Circuit of Figure 1, V+ = 15V, V
CC
= V
DD
= V
SHDN
= V
SKIP
= V
S0
= V
S1
= 5V, V
FB
= V
CMP
= V
CMN
= V
CSP
= V
CSN
= 1.3V, OFS =
SUS = GNDS = D0–D5 = GND,
T
A
= 0°C to +85°C,
unless otherwise specified. Typical values are at T
A
= +25°C.)
PARAMETER
PWM CONTROLLER
Input Voltage Range
DC Output Voltage Accuracy
(Note 2)
Line Regulation Error
Input Bias Current
OFS Input Range
∆V
OUT
/∆V
OFS;
∆V
OFS
= V
OFS,
V
OFS
= 0 to 1V
∆V
OUT
/∆V
OFS;
∆V
OFS
= V
OFS
- V
REF,
V
OFS
= 1V to 2V
∆V
OUT
/∆V
GNDS
1000kHz nominal, R
TIME
= 15kΩ
TIME Frequency Accuracy
f
TIME
500kHz nominal, R
TIME
= 30kΩ
250kHz nominal, R
TIME
= 60kΩ
Startup and shutdown, R
TIME
= 30kΩ
I
FB
, I
GNDS
I
OFS
Battery voltage, V+
V
CC
, V
DD
V+ = 4.5V to 28V,
includes load
regulation error
DAC codes
≥
1V
DAC codes from
0.375V to 1V
4
4.5
-10
-15
5
-2
-0.1
0
-0.129
-0.129
-20
A
GNDS
0.97
900
460
225
0.99
1000
500
250
125
-0.125
-0.125
+2
+0.1
2
-0.117
V/V
-0.117
+200
1.01
1100
540
275
kHz
mV
V/V
28
5.5
+10
+15
mV
mV
µA
V
V
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
V
CC
= 4.5V to 5.5V, V+ = 4.5V to 28V
FB, GNDS
OFS
OFS Gain
A
OFS
GNDS Input Range
GNDS Gain
2
_______________________________________________________________________________________
Dual-Phase, Quick-PWM Controller for AMD
Mobile Turion 64 CPU Core Power Supplies
ELECTRICAL CHARACTERISTICS (continued)
(Circuit of Figure 1, V+ = 15V, V
CC
= V
DD
= V
SHDN
= V
SKIP
= V
S0
= V
S1
= 5V, V
FB
= V
CMP
= V
CMN
= V
CSP
= V
CSN
= 1.3V, OFS =
SUS = GNDS = D0–D5 = GND,
T
A
= 0°C to +85°C,
unless otherwise specified. Typical values are at T
A
= +25°C.)
PARAMETER
SYMBOL
CONDITIONS
TON = GND
(550kHz)
TON = REF
(300kHz)
TON = open
(200kHz)
TON = V
CC
(100kHz)
Minimum Off-Time (Note 3)
BIAS AND REFERENCE
Quiescent Supply Current (V
CC
)
Quiescent Supply Current (V
DD
)
Quiescent Battery Supply Current
(V+)
Shutdown Supply Current (V
CC
)
Shutdown Supply Current (V
DD
)
Shutdown Battery Supply Current
(V+)
Reference Voltage
Reference Load Regulation
FAULT PROTECTION
Output Overvoltage Protection
Threshold
Output Overvoltage Propagation
Delay
Output Undervoltage Protection
Threshold
Output Undervoltage Propagation
Delay
V
OVP
t
OVP
V
UVP
t
UVP
FB forced 2% above trip threshold
Measured at FB with respect to unloaded
output voltage
FB forced 2% below trip threshold
Lower threshold
(undervoltage)
Upper threshold
(overvoltage)
SKIP
= V
CC
-12
67
2.00
10
70
10
-10
-8
%
+8
+10
+12
73
V
µs
%
µs
V
REF
∆V
REF
I
CC
I
DD
I
V+
Measured at V
CC
, FB forced above the
regulation point, OAIN- = FB, V
OAIN+
= 1.3V
Measured at V
DD
, FB forced above the
regulation point
Measured at V+
Measured at V
CC
,
SHDN
= GND
Measured at V
DD
,
SHDN
= GND
Measured at V+,
SHDN
= GND,
V
CC
= V
DD
= 0V or 5V
V
CC
= 4.5V to 5.5V, I
REF
= 0
I
REF
= -10µA to 100µA
1.990
-10
1.70
<1
25
4
<1
<1
2.000
3.20
5
40
10
5
5
2.010
+10
mA
µA
µA
µA
µA
µA
V
mV
t
OFF(MIN)
TON = GND
TON = V
CC
, open, or REF
MIN
155
320
475
920
TYP
180
355
525
1000
300
400
MAX
205
390
ns
575
1140
375
480
ns
UNITS
MAX8760
On-Time (Note 3)
t
ON
V+ = 12V,
V
FB
= V
CCI
= 1.2V
VROK Threshold
Measured at FB
with respect to
unloaded output
voltage
_______________________________________________________________________________________
3
Dual-Phase, Quick-PWM Controller for AMD
Mobile Turion 64 CPU Core Power Supplies
MAX8760
ELECTRICAL CHARACTERISTICS (continued)
(Circuit of Figure 1, V+ = 15V, V
CC
= V
DD
= V
SHDN
= V
SKIP
= V
S0
= V
S1
= 5V, V
FB
= V
CMP
= V
CMN
= V
CSP
= V
CSN
= 1.3V, OFS =
SUS = GNDS = D0–D5 = GND,
T
A
= 0°C to +85°C,
unless otherwise specified. Typical values are at T
A
= +25°C.)
PARAMETER
Output Undervoltage Fault and
VROK Transition Blanking Time
SYMBOL
t
BLANK
CONDITIONS
Measured from the time when FB reaches
the voltage set by the DAC code; clock
speed set by R
TIME
(Note 4)
Measured from the time when FB first
reaches the voltage set by the DAC code
after startup
t
VROK
FB forced 2% outside the VROK trip
threshold
I
SINK
= 3mA
High state, VROK forced to 5.5V
V
UVLO(VCC)
T
SHDN
Rising edge, hysteresis = 90mV, PWM
disabled below this level
Hysteresis = 10°C
4.0
4.25
+160
3
MIN
TYP
24
MAX
UNITS
Clks
VROK Startup Delay
5
7
ms
VROK Delay
VROK Output Low Voltage
VROK Leakage Current
V
CC
Undervoltage Lockout
Threshold
Thermal-Shutdown Threshold
CURRENT LIMIT AND BALANCE
Current-Limit Threshold Voltage
(Positive, Default)
Current-Limit Threshold Voltage
(Positive, Adjustable)
Current-Limit Threshold Voltage
(Negative)
Current-Limit Threshold Voltage
(Zero Crossing)
CMP, CMN, CSP, CSN Input
Ranges
CMP, CMN, CSP, CSN Input
Current
Secondary Driver-Disable
Threshold
ILIM Input Current
Current-Limit Default Switchover
Threshold
Current-Balance Offset
10
0.4
1
4.4
µs
V
µA
V
°C
V
LIMIT
V
LIMIT
V
LIMIT(NEG)
V
ZERO
CMP - CMN, CSP - CSN; ILIM = V
CC
CMP - CMN, CSP - CSN
V
ILIM
= 0.2V
V
ILIM
= 1.5V
28
8
73
-41
30
10
75
-36
1.5
32
12
77
-31
mV
mV
mV
mV
CMP - CMN, CSP - CSN; ILIM = V
CC
,
SKIP
= V
CC
CMP - CMN, CSP - CSN;
SKIP
= GND
0
V
CSP
= V
CSN
= 0 to 5V
V
CSP
I
ILIM
V
ILIM
(V
CMP
- V
CMN
) - (V
CSP
- V
CSN
); I
CCI
= 0,
-20mV < (V
CMP
- V
CMN
) < 20mV,
1.0V < V
CCI
< 2.0V
V
ILIM
= 0 to 5V
3
-2
3
V
CC
- 1
0.1
V
CC
- 1
2
+2
V
CC
-
0.4
200
V
CC
-
0.4
+2
V
µA
V
nA
V
V
OS(IBAL)
-2
mV
4
_______________________________________________________________________________________
Dual-Phase, Quick-PWM Controller for AMD
Mobile Turion 64 CPU Core Power Supplies
ELECTRICAL CHARACTERISTICS (continued)
(Circuit of Figure 1, V+ = 15V, V
CC
= V
DD
= V
SHDN
= V
SKIP
= V
S0
= V
S1
= 5V, V
FB
= V
CMP
= V
CMN
= V
CSP
= V
CSN
= 1.3V, OFS =
SUS = GNDS = D0–D5 = GND,
T
A
= 0°C to +85°C,
unless otherwise specified. Typical values are at T
A
= +25°C.)
PARAMETER
Current-Balance
Transconductance
GATE DRIVERS
DH_ Gate-Driver On-Resistance
DL_ Gate-Driver On-Resistance
DH_ Gate-Driver Source/Sink
Current
DL_ Gate-Driver Sink Current
DL_ Gate-Driver Source Current
Dead Time
VOLTAGE-POSITIONING AMPLIFIER
Input Offset Voltage
Input Bias Current
Op Amp Disable Threshold
Common-Mode Input Voltage
Range
Common-Mode Rejection Ratio
Power-Supply Rejection Ratio
Large-Signal Voltage Gain
Output Voltage Swing
Input Capacitance
Gain-Bandwidth Product
Slew Rate
Capacitive-Load Stability
LOGIC AND I/O
SHDN
Input High Voltage
SHDN
Input Low Voltage
SHDN
No-Fault Threshold
Three-Level Input Logic Levels
Logic Input Current
D0–D5 Logic Input High Voltage
V
IH
V
IL
V
SHDN
To enable no-fault mode
High
SUS,
SKIP
SHDN, SKIP,
SUS
REF
Low
-1
1.6
12
2.7
1.2
2.3
0.8
+1
µA
V
V
0.8
0.4
15
V
V
V
No sustained oscillations
V
OS
I
BIAS
V
OAIN-
V
CM
CMRR
PSRR
A
OA
Guaranteed by CMRR test
V
OAIN+
= V
OAIN-
= 0 to 2.5V
V
CC
= 4.5V to 5.5V
R
L
= 1kΩ to V
CC
/2
|V
OAIN+
- V
OAIN-
|
≥
10mV,
R
L
= 1kΩ to V
CC
/2
V
CC
- V
FBH
V
FBL
OAIN+, OAIN-
3
0
70
75
80
115
100
112
77
47
11
3
0.3
400
300
200
-1
0.1
V
CC
- 1
+1
200
V
CC
-
0.4
2.5
mV
nA
V
V
dB
dB
dB
mV
pF
MHz
V/µs
pF
R
ON(DH)
R
ON(DL)
I
DH
I
DL(SINK)
BST_ - LX_ forced to 5V
High state (pullup)
Low start (pulldown)
DH_ forced to 2.5V,
BST_ - LX_ forced to 5V
DL_ forced to 5V
DL_ rising
DH_ rising
1.0
1.0
0.4
1.6
4
1.6
35
26
4.5
4.5
2
Ω
Ω
A
A
A
ns
SYMBOL
G
m(IBAL)
CONDITIONS
MIN
TYP
400
MAX
UNITS
µS
MAX8760
I
DL(SOURCE)
DL_ forced to 2.5V
t
DEAD
_______________________________________________________________________________________
5