XRP7724
Quad Channel Digital PWM/PFM
Programmable Power Management System
October 2012
Rev. 1.0.1
GENERAL DESCRIPTION
The XRP7724 is a quad channel Digital Pulse
Width Modulated (DPWM) Step down (buck)
controller. A wide 4.75V to 5.5V and 5.5V to
25V input voltage dual range allows for single
supply operation from standard power rails.
With integrated FET gate drivers, two LDOs for
standby power and a 105kHz to 1.23MHz
independent channel to channel programmable
constant operating frequency, the XRP7724
reduces overall component count and solution
footprint and optimizes conversion efficiencies.
A selectable digital Pulse Frequency Mode
(DPFM) capable of better than 80% efficiency
at light current load and low operating current
allow for portable and Energy Star compliant
applications. Each XRP7724 output channel is
individually programmable as low as 0.6V with
a resolution as fine as 2.5mV, and
configurable for precise soft start and soft stop
sequencing, including delay and ramp control.
The XRP7724 operations are fully controlled
via a SMBus-compliant I
2
C interface allowing
for
advanced
local
and/or
remote
reconfiguration, full performance monitoring
and reporting as well as fault handling.
Built-in independent output over voltage, over
temperature, over-current and under voltage
lockout protections insure safe operation
under abnormal operating conditions.
The XRP7724 is offered in a RoHS compliant,
“green”/halogen free 44-pin TQFN package.
APPLICATIONS
Servers
Base Stations
Switches/Routers
Broadcast Equipment
Industrial Control Systems
Automatic Test Equipment
Video Surveillance Systems
FEATURES
Quad Channel Step-down Controller
Digital PWM 105kHz-1.23MHz Operations
Individual Channel Frequency Selection
Patented digital PFM with Ultrasonic mode
Patented Over Sampling Feedback
Integrated MOSFET Drivers
Programmable 5 coefficient PID control
4.75V to 25V Input Voltage
4.75V-5.5 and 5.5V-25V Input Ranges
0.6V to 5.5V Output voltage
SMBus Compliant - I
2
C Interface
Full Power Monitoring and Reporting
3 x 15V Capable PSIO + 2 x GPIOs
Full Start/Stop Sequencing Support
Built-in Thermal, Over-Current, UVLO
and Output Over-Voltage Protections
On Board 5V and 3.3V Standby LDOs
On Board Non-volatile Memory
Supported by PowerArchitect™
TYPICAL APPLICATION DIAGRAM
Fig. 1: XRP7724 Application Diagram
Exar Corporation
48720 Kato Road, Fremont CA 94538, USA
www.exar.com
Tel. +1 510 668-7000 – Fax. +1 510 668-7001
XRP7724
Quad Channel Digital PWM/PFM
Programmable Power Management System
ABSOLUTE MAXIMUM RATINGS
These are stress ratings only and functional operation of
the device at these ratings or any other above those
indicated in the operation sections of the specifications
below is not implied. Exposure to absolute maximum
rating conditions for extended periods of time may affect
reliability.
VCCD, LDO5, LDO3_3, GLx, VOUTx ............. -0.3V to 7.0V
ENABLE, 5V_EXT ....................................... -0.3V to 7.0V
GPIO0/1, SCL, SDA................................................ 6.0V
PSIOs Inputs, BFB .................................................. 18V
DVDD, AVDD ........................................................ 2.0V
VCC ...................................................................... 28V
LX# ............................................................. -1V to 28V
BSTx, GHx .................................................... VLXx + 6V
Storage Temperature .............................. -65°C to 150°C
Power Dissipation ................................ Internally Limited
Lead Temperature (Soldering, 10 sec).................... 300°C
ESD Rating (HBM - Human Body Model) .................... 2kV
OPERATING RATINGS
Input Voltage Range V
CC
............................... 5.5V to 25V
Input Voltage Range V
CC
= LDO5 ................ 4.75V to 5.5V
VOUT1, 2, 3, 4 ...................................................... 5.5V
Junction Temperature Range ....................-40°C to 125°C
JEDEC Thermal Resistance θ
JA
..........................30.2°C/W
ELECTRICAL SPECIFICATIONS
Specifications with standard type are for an Operating Junction Temperature of T
J
= 25°C only; limits applying over the full
Operating Junction Temperature range are denoted by a “•”. Minimum and Maximum limits are guaranteed through test,
design, or statistical correlation. Typical values represent the most likely parametric norm at T
J
= 25°C, and are provided for
reference purposes only. Unless otherwise indicated, V
CC
= 5.5V to 25V, 5V EXT open. Note that in cases where there is a
discrepancy in values shown in this section and other sections of the datasheet, the values in the Electrical Specification
section shall be deemed correct and supersede the other values.
Q
UIESCENT
C
URRENT
Parameter
VCC Supply Current in SHUTDOWN
ENABLE Turn On Threshold
ENABLE Pin Leakage Current
0.82
Min.
Typ.
10
Max.
20
0.95
10
-10
440
600
µA
Units
µA
V
uA
Conditions
EN = 0V, VCC = 12V
VCC = 12V Enable Rising
EN=5V
EN=0V
LDO3_3 disabled, all channels disabled
VCC Supply Current in STANDBY
GPIOs programmed as inputs
VCC=12V,EN = 5V
VCC Supply Current 2ch PFM
3.1
mA
2 channels on set at 5V, VOUT forced to
5.1V, no load, non-switching, Ultra-sonic
off, VCC=12 V, No I
2
C activity.
4 channels on set at 5V, VOUT forced to
5.1V, no load, non-switching, Ultra-sonic
off, VCC=12V, No I
2
C activity.
All channels enabled, Fsw=600kHz, gate
drivers unloaded, No I
2
C activity.
VCC Supply Current 4ch PFM
4.0
mA
VCC Supply Current ON
18
mA
© 2012 Exar Corporation
2/29
Rev. 1.0.1
XRP7724
Quad Channel Digital PWM/PFM
Programmable Power Management System
I
NPUT
V
OLTAGE
R
ANGE AND
U
NDERVOLTAGE
L
OCKOUT
Parameter
VCC Range
Min.
5.5
4.75
Typ.
Max.
25
5.5
Units
V
V
•
•
Conditions
With VCC connected to LDO5
V
OLTAGE
F
EEDBACK
A
CCURACY AND
O
UTPUT
V
OLTAGE
S
ET
P
OINT
R
ESOLUTION
Parameter
VOUT Regulation Accuracy
Low Output Range
0.6V to 1.6V
PWM Operation
VOUT Regulation Accuracy
Mid Output Range
0.6V to 3.2V
PWM Operation
VOUT Regulation Accuracy
High Output Range
0.6V to 5.5V
PWM Operation
VOUT Regulation Range
VOUT Native Set Point
Resolution
VOUT Fine Set Point Resolution
1
Min.
-5
-20
-7.5
-22.5
-15
-45
-20
-50
-30
-90
-40
-100
0.6
12.5
25
50
2.5
5
10
120
90
75
10
1
0.67
-155
-310
-620
-5
-10
-20
9
1
-0.5
0.5
157.5
315
630
5
10
20
16
Typ.
Max.
5
20
7.5
22.5
15
45
20
50
30
90
40
100
5.5
Units
mV
mV
mV
mV
mV
mV
mV
mV
mV
mV
mV
mV
V
mV
•
•
•
•
•
•
•
Conditions
0.6 ≤ VOUT ≤ 1.6V
0.6 ≤ VOUT ≤ 1.6V
VCC=LDO5
0.6 ≤ VOUT ≤ 3.2V
0.6 ≤ VOUT ≤ 3.2V
VCC=LDO5
0.6 ≤ VOUT ≤ 5.5V
0.6 ≤ VOUT ≤ 4.2V
VCC=LDO5
Without external divider network
Low Range
Mid Range
High Range
Low Range
Mid Range
High Range
Low Range
Mid Range
High Range
Low Range
Mid Range
High Range
Low Range
Mid Range
High Range
Low Range
Mid Range
High Range
mV
VOUT Input Resistance
VOUT Input Resistance in PFM
Operation
Power Good and OVP Set Point
Range (from set point)
Power Good and OVP Set Point
Accuracy
BFB Set Point Range
BFB Set Point Resolution
BFB Accuracy
kΩ
MΩ
mV
mV
V
V
V
Note 1: Fine Set Point Resolution not available in PFM
© 2012 Exar Corporation
3/29
Rev. 1.0.1
XRP7724
Quad Channel Digital PWM/PFM
Programmable Power Management System
C
URRENT AND
AUX ADC (M
ONITORING
ADC
S
)
Parameter
Min.
-3.75
-10
-5
-12.5
Typ.
±1.25
±2.5
+/-0.4
0.27
1.25
2.5
-120
-280
15
30
60
-1
4.6
4.4
4.4
4.2
200
-1
5
-44
156
1
1
25
4.72
4.72
4.55
20
40
mV
LSB
V
V
V
V
mV
LSB
°C
°C
Output value is in Kelvin
Vin <= 20V
Note 3
UVLO WARN set point 4.6V, VCC=LDO5
UVLO WARN set point 4.6V, VCC=LDO5
UVLO FAULT set point 4.4V, VCC=LDO5
mV
mV
mV
Low Range (≤120mV)
High Range (≤280mV)
Low Range (≤120mV)
High Range (≤280mV)
Low Range
Mid Range
High Range
Max.
3.75
10
5
+12.5
Units
mV
mV
mV
mV
LSB
•
•
Conditions
Low Range (≤120mV) Note 2
-60mV applied
High Range (≤280mV)
-150mV
Current Sense Accuracy
Current Sense ADC INL
DNL
Current Limit Set Point
Resolution and Current
Sense ADC Resolution
Current Sense ADC Range
VOUT ADC Resolution
VOUT ADC Accuracy
VCC ADC Range
UVLO WARN SET
UVLO WARN CLEAR
UVLO FAULT SET (Note 4)
VCC ADC Resolution
VCC ADC Accuracy
Die Temp ADC Resolution
Die Temp ADC Range
Note 2: Final test limits are ±2.5mV or ±2 LSB
Note 3: Although Range of VCC ADC is technically 0V to 25V, below 4.55 the LDO5 hardware UVLO may have tripped.
Note 4: This test ensures an UVLO FAULT flag will be given before the LDO5 hardware UVLO trips.
L
INEAR
R
EGULATORS
Parameter
LDO5 Output Voltage
LDO5 Current Limit
LDO5 UVLO
LDO5 PGOOD Hysteresis
LDO5 Bypass Switch Resistance
Bypass Switch Activation
Threshold
Bypass Switch Activation
Hysteresis
LDO3_3 Output Voltage
LDO3_3 Current Limit
Maximum total LDO loading
during ENABLE start-up
3.15
53
2.5
150
3.3
3.45
85
30
Min.
4.85
135
4.74
375
1.1
1.5
2.5
Typ.
5.0
155
Max.
5.15
180
Units
V
mA
V
mV
Ω
%
mV
V
mA
mA
•
•
•
V5EXT Rising, % of threshold setting
V5EXT Falling
4.6V ≤ LDO5 ≤ 5.5V
0mA < I
LDO3_3OUT
< 50mA
LDO3_3 Fault Set
ENABLE transition from logic low to
high. Once LDO5 in regulation above
limits apply.
•
•
•
Conditions
5.5V ≤ VCC ≤ 25V
0mA < I
LDO5OUT
< 130mA, LDO3_3 Off
LDO5 Fault Set
VCC Rising
VCC Falling
© 2012 Exar Corporation
4/29
Rev. 1.0.1
XRP7724
Quad Channel Digital PWM/PFM
Programmable Power Management System
PWM G
ENERATORS AND
O
SCILLATOR
Parameter
Switching Frequency (fsw)
Range
fsw Accuracy
CLOCK IN
Synchronization Frequency
CLOCK IN
Synchronization Frequency
Min.
105
–5
20
10
25.7
12.8
Typ.
Max.
1230
5
31
15.5
Units
kHz
%
MHz
MHz
When synchronizing to an external clock
(Range 1)
When synchronizing to an external clock
(Range 2)
Conditions
Steps defined in table
GPIO
S
5
Parameter
Input Pin Low Level
Input Pin High Level
Input Pin Leakage Current
Output Pin Low Level
Output Pin High Level
Output Pin High Level
Output Pin High-Z leakage
Current (GPIO pins only)
Maximum Sink Current
I/O Frequency
Note 5: 3.3V CMOS logic compatible, 5V tolerant.
2.4
3.3
3.6
10
1
30
2.0
1
0.4
Min.
Typ.
Max.
0.8
Units
V
V
µA
V
V
V
µA
mA
MHz
Open Drain Mode
I
SINK
= 1mA
I
SOURCE
= 1mA
I
SOURCE
= 0mA
Conditions
PSIO
S
6
Parameter
Input Pin Low Level
Input Pin High Level
Input Pin Leakage Current
Output Pin Low Level
Output Pin High Level
Output Pin High-Z leakage
Current (PSIO pins only)
I/O Frequency
2.0
1
0.4
15
10
5
Min.
Typ.
Max.
0.8
Units
V
V
µA
V
V
µA
MHz
I
SINK
= 3mA
Open Drain. External pull-up resistor to
user supply
Conditions
Note 6: 3.3V/5.0V CMOS logic compatible, maximum rating of 15.0V
© 2012 Exar Corporation
5/29
Rev. 1.0.1
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