Radiation Hardened and SEE Hardened 6A
Synchronous Buck Regulator with Integrated MOSFETs
ISL70001SRH
The ISL70001SRH is a radiation hardened and SEE hardened
high efficiency monolithic synchronous buck regulator with
integrated MOSFETs. This single chip power solution operates
over an input voltage range of 3V to 5.5V and provides a tightly
regulated output voltage that is externally adjustable from 0.8V
to ~85% of the input voltage. Output load current capacity is 6A
for T
J
< +145°C
.
The ISL70001SRH utilizes peak current-mode control with
integrated compensation and switches at a fixed frequency of
1MHz. Two ISL70001SRH devices can be synchronized 180°
out-of-phase to reduce input RMS ripple current. These attributes
reduce the number and size of external components required,
while providing excellent output transient response. The
internal synchronous power switches are optimized for high
efficiency and good thermal performance.
The chip features a comparator type enable input that provides
flexibility. It can be used for simple digital on/off control or,
alternately, can provide undervoltage lockout capability by
using two external resistors to precisely sense the level of an
external supply voltage. A power-good signal indicates when the
output voltage is within ±11% typical of the nominal output
voltage.
Regulator start-up is controlled by an analog soft-start circuit,
which can be adjusted from approximately 2ms to 200ms by
using an external capacitor.
The ISL70001SRH incorporates fault protection for the
regulator. The protection circuits include input undervoltage,
output undervoltage, and output overcurrent.
High integration makes the ISL70001SRH an ideal choice to
power many of today’s small form factor applications. Two
devices can be synchronized to provide a complete power
solution for large scale digital ICs, like field programmable gate
arrays (FPGAs), that require separate core and I/O voltages.
Specifications for Rad Hard QML devices are controlled by the
Defense Supply Center in Columbus (DSCC). The SMD numbers
listed in the Ordering Information table on page 2 must be used
when ordering.
Detailed Electrical Specifications for these devices are contained
in
SMD 5962-09225.
This link is also available on the
ISL70001SRH device information page
on the Intersil web site.
Features
• Electrically Screened to DSCC SMD 5962-09225
• QML Qualified per MIL-PRF-38535 Requirements
• Full Mil-Temp Range Operation (T
A
= -55°C to +125°C)
• Radiation Hardness
- Total Dose [50-300rad(Si)/s] . . . . . . . . . . .100krad(Si) min
• SEE Hardness
- SEL and SEB LET
eff
. . . . . . . . . . . . 86.4MeV/mg/cm
2
min
- SEFI X-section (LET
eff
= 86.4MeV/mg/cm
2
) 1.4 x 10
-6
cm
2
max
- SET LET
eff
(< 1 Pulse Perturbation) 86.4MeV/mg/cm
2
min
• High Efficiency > 90%
• Fixed 1MHz Operating Frequency
• Operates from 3V to 5.5V Supply
• ±1% Reference Voltage over Line, Load, Temperature and
Radiation
• Adjustable Output Voltage
- Two External Resistors Set V
OUT
from 0.8V to ~85% of V
IN
• Excellent Dynamic Response
• Bi-directional SYNC Pin Allows Two Devices to be Synchronized
180
°
Out-of-Phase
• Device Enable with Comparator Type Input
• Power-Good Output Voltage Monitor
• Adjustable Analog Soft-Start
• Input Undervoltage, Output Undervoltage and Output
Overcurrent Protection
• Starts Into Pre-Biased Load
Applications
• FPGA, CPLD, DSP, CPU Core or I/O Voltages
• Low-Voltage, High-Density Distributed Power Systems
May 23, 2011
FN6947.1
1
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
1-888-INTERSIL or 1-888-468-3774
|
Copyright Intersil Americas Inc. 2009, 2011. All Rights Reserved
Intersil (and design) is a trademark owned by Intersil Corporation or one of its subsidiaries.
All other trademarks mentioned are the property of their respective owners.
ISL70001SRH
Functional Block Diagram
AVDD
AGND
DVDD
DGND
EN
PORSEL
POWER-ON
RESET (POR)
PVINx
CURRENT
SENSE
SS
SOFT
START
SLOPE
COMPENSATION
PWM
CONTROL
LOGIC
FB
EA
GM
GATE
DRIVE
LXx
COMPENSATION
PGNDx
PGOOD
UV
POWER-GOOD
REF
PWM
REFERENCE
0.6V
TDI
BIT
TDO
TRIM
ZAP
SYNC
M/S
Ordering Information
ORDERING NUMBER
5962R0922501QXC
5962R0922501VXC
5962R0922501V9A
ISL70001SRHF/PROTO
ISL70001SRHX/SAMPLE
ISL70001SRHEVAL1Z
PART NUMBER
(Note 2)
ISL70001SRHQF (Note 1)
ISL70001SRHVF (Note 1)
ISL70001SRHVX
ISL70001SRHF/PROTO (Note 1)
ISL70001SRHX/SAMPLE
Evaluation Board
TEMP. RANGE
(°C)
-55 to +125
-55 to +125
-55 to +125
-55 to +125
-55 to +125
PACKAGE
48 Ld CQFP (Pb-Free)
48 Ld CQFP (Pb-Free)
Die
48 Ld CQFP (Pb-Free)
Die
NOTE:
1. These Intersil Pb-free Hermetic packaged products employ 100% Au plate - e4 termination finish, which is RoHS compliant and compatible with both
SnPb and Pb-free soldering operations.
2. For Moisture Sensitivity Level (MSL), please see device information page for
ISL70001SRH.
For more information on MSL, please see Tech Brief
TB363.
2
FN6947.1
May 23, 2011
ISL70001SRH
Pin Configuration
ISL70001SRH
(48 LD CQFP)
TOP VIEW
PGND1
PGND1
PGND2
PGND2
PVIN1
PVIN1
PVIN2
PVIN2
PVIN3
SYNC
LX1
LX2
6
M/S
ZAP
TDI
TDO
PGOOD
SS
DVDD
DVDD
DGND
DGND
AGND
AGND
7
8
9
10
11
12
13
14
15
16
17
5
4
3
2
1 48 47 46 45 44 43
42
41
40
39
38
37
36
35
34
33
32
PVIN3
LX3
PGND3
PGND3
PGND4
PGND4
LX4
PVIN4
PVIN4
PVIN5
PVIN5
LX5
31
18
19 20 21 22 23 24 25 26 27 28 29 30
PORSEL
AVDD
REF
LX6
PGND6
PGND6
PGND5
Pin Descriptions
PIN NUMBER
1, 2, 27, 28, 29, 30,
37, 38, 39, 40, 47,
48
3, 26, 31, 36, 41,
46
PIN NAME
PGNDx
DESCRIPTION
These pins are the power grounds associated with the corresponding internal power blocks. Connect these pins
directly to the ground plane. These pins should also connect to the negative terminals of the input and output
capacitors. Locate the input and output capacitors as close as possible to the IC.
These pins are the outputs of the corresponding internal power blocks and should be connected to the output
filter inductor. Internally, these pins are connected to the synchronous MOSFET power switches. To minimize
voltage undershoot, it is recommended that a Schottky diode be connected from these pins to PGNDx. The
Schottky diode should be located as close as possible to the IC.
These pins are the power supply inputs to the corresponding internal power blocks. These pins must be
connected to a common power supply rail, which must fall in the range of 3V to 5.5V. Bypass these pins directly
to PGNDx with ceramic capacitors located as close as possible to the IC.
This pin is the synchronization I/O for the IC. When configured as an output (Master Mode), this pin drives the
SYNC input of another ISL70001SRH. When configured as an input (Slave Mode), this pin accepts the SYNC
output from another ISL70001SRH or an external clock. Synchronization of the slave unit is 180° out-of-phase
with respect to the master unit. If synchronizing to an external clock, the clock must be SEE hardened and the
frequency must be within the range of 1MHz ±20%.
This pin is the Master/Slave input for selecting the direction of the bi-directional SYNC pin. For SYNC = Output
(Master Mode), connect this pin to DVDD. For SYNC = Input (Slave Mode), connect this pin to DGND.
This pin is a trim input and is used to adjust various internal circuitry. Connect this pin to DGND.
This pin is the test data input of the internal BIT circuitry. Connect this pin to DGND.
This pin is the test data output of the internal BIT circuitry. Connect this pin to DGND.
This pin is the power-good output. This pin is an open drain logic output that is pulled to DGND when the output
voltage is outside a ±11% typical regulation window. This pin can be pulled up to any voltage from 0V to 5.5V,
independent of the supply voltage. A nominal 1kΩ to 10kΩ pull-up resistor is recommended. Bypass this pin
to DGND with a 10nF ceramic capacitor to mitigate SEE.
LXx
4, 5, 24, 25, 32, 33,
34, 35, 42, 43, 44,
45
6
PVINx
SYNC
7
8
9
10
11
M/S
ZAP
TDI
TDO
PGOOD
3
PGND5
PVIN6
PVIN6
FB
EN
FN6947.1
May 23, 2011
ISL70001SRH
Pin Descriptions
(Continued)
PIN NUMBER
12
PIN NAME
SS
DESCRIPTION
This pin is the soft-start input. Connect a ceramic capacitor from this pin to DGND to set the soft-start output
ramp time in accordance with Equation 1:
t
SS
=
C
SS
⋅
V
REF
⁄
I
SS
(EQ. 1)
Where:
t
SS
= Soft-start output ramp time
C
SS
= Soft-start capacitor
V
REF
= Reference voltage (0.6V typical)
I
SS
= Soft-start charging current (23µA typical)
Soft-start time is adjustable from approximately 2ms to 200ms.
The range of the soft-start capacitor should be 82nF to 8.2µF, inclusive.
13, 14
DVDD
These pins are the bias supply inputs to the internal digital control circuitry. Connect these pins together at the
IC and locally filter them to DGND using a 1Ω resistor and a 1µF ceramic capacitor. Locate both filter
components as close as possible to the IC.
These pins are the digital ground associated with the internal digital control circuitry. Connect these pins
directly to the ground plane.
These pins are the analog ground associated with the internal analog control circuitry. Connect these pins
directly to the ground plane.
This pin is the bias supply input to the internal analog control circuitry. Locally filter this pin to AGND using a 1Ω
resistor and a 1µF ceramic capacitor. Locate both filter components as close as possible to the IC.
This pin is the internal reference voltage output. Bypass this pin to AGND with a 220nF ceramic capacitor
located as close as possible to the IC. The bypass capacitor is needed to mitigate SEE. No current (sourcing or
sinking) is available from this pin.
This pin is the voltage feedback input to the internal error amplifier. Connect a resistor from FB to VOUT and
from FB to AGND to adjust the output voltage in accordance with Equation 2:
V
OUT
=
V
REF
⋅ [
1
+
(
R
T
⁄
R
B
) ]
(EQ. 2)
15, 16
17, 18
19
20
DGND
AGND
AVDD
REF
21
FB
Where:
V
OUT
= Output voltage
V
REF
= Reference voltage (0.6V typical)
R
T
= Top divider resistor (Must be 1kΩ)
R
B
= Bottom divider resistor
The top divider resistor must be 1kΩ to mitigate SEE. Connect a 4.7nF ceramic capacitor across RT to mitigate SEE
and to improve stability margins.
22
EN
This pin is the enable input to the IC. This is a comparator type input with a rising threshold of 0.6V and
programmable hysteresis. Driving this pin above 0.6V enables the IC. Bypass this pin to AGND with a 10nF
ceramic capacitor to mitigate SEE.
This pin is the input for selecting the rising and falling POR (Power-On-Reset) thresholds. For a nominal 5V
supply, connect this pin to DVDD. For a nominal 3.3V supply, connect this pin to DGND. For nominal supply
voltages between 5V and 3.3V, connect this pin to DGND.
23
PORSEL
4
FN6947.1
May 23, 2011
ISL70001SRH
Typical Application Schematic
PVIN1
5V
PVIN2
100µF
1µF
PVIN3
LX3
LX2
LX1
PVIN4
LX4
PVIN5
1µF
PVIN6
LX5
1µH
LX6
20V
3A
FB
ISL70001SRH
0V TO 5.5V
499Ω
470µF
1kΩ
4.7nF
1.8V
6A
1
DVDD
1µF
DGND
1
AVDD
1µF
AGND
PGOOD
10nF
VSENSE
SYNC
EN
REF
220nF
10nF
M/S
PORSEL
TDI
TDO
ZAP
SS
100nF
PGND4
PGND1
FIGURE 1. 5V INPUT SUPPLY VOLTAGE WITH MASTER MODE SYNCHRONIZATION
5
PGND2
PGND3
PGND5
PGND6
FN6947.1
May 23, 2011
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