DATASHEET
ISL8840A, ISL8841A, ISL8842A, ISL8843A, ISL8844A, ISL8845A
High Performance Industry Standard Single-Ended Current Mode PWM Controller
FN6320
Rev 3.00
April 18, 2007
The ISL884xA is a high performance drop-in replacement for
the popular 28C4x and 18C4x PWM controllers suitable for a
wide range of power conversion applications including
boost, flyback, and isolated output configurations. Its fast
signal propagation and output switching characteristics
make this an ideal product for existing and new designs.
Features include 30V operation, low operating current, 90A
start-up current, adjustable operating frequency to 2MHz,
and high peak current drive capability with 20ns rise and fall
times.
PART NUMBER
ISL8840A
ISL8841A
ISL8842A
ISL8843A
ISL8844A
ISL8845A
RISING UVLO
7.0
7.0
14.4V
8.4V
14.4V
8.4V
MAX. DUTY CYCLE
100%
50%
100%
100%
50%
50%
Features
• 1A MOSFET gate driver
• 90A start-up current, 125A maximum
• 35ns propagation delay current sense to output
• Fast transient response with peak current mode control
• 30V operation
• Adjustable switching frequency to 2MHz
• 20ns rise and fall times with 1nF output load
• Trimmed timing capacitor discharge current for accurate
deadtime/maximum duty cycle control
• 1.5MHz bandwidth error amplifier
• Tight tolerance voltage reference over line, load and
temperature
• ±3% current limit threshold
• Pb-free plus anneal available
and ELV, WEEE, RoHS
Compliant
Pinout
ISL8840A, ISL8841A, ISL8842A, ISL8843A, ISL8844A, ISL8845A
(8 LD SOIC, MSOP)
TOP VIEW
COMP 1
FB 2
CS 3
RTCT 4
8 VREF
7 VDD
6 OUT
5 GND
Applications
• Telecom and datacom power
• Wireless base station power
• File server power
• Industrial power systems
• PC power supplies
• Isolated buck and flyback regulators
• Boost regulators
FN6320 Rev 3.00
April 18, 2007
Page 1 of 15
ISL8840A, ISL8841A, ISL8842A, ISL8843A, ISL8844A, ISL8845A
Ordering Information
PART
NUMBER*
ISL8840AABZ
(See Note)
PART
MARKING
8840 AABZ
TEMP.
PACKAGE PKG.
RANGE (°C) (Pb-free) DWG. #
-40 to +105 8 Ld SOIC
M8.15
Ordering Information
(Continued)
PART
NUMBER*
PART
MARKING
TEMP.
PACKAGE PKG.
RANGE (°C) (Pb-free) DWG. #
-55 to +125 8 Ld SOIC
M8.15
ISL8843AMBZ 8843 AMBZ
(See Note)
ISL8843AMUZ 43AMZ
(See Note)
ISL8844AABZ
(See Note)
8844 AABZ
ISL8840AAUZ 40AAZ
(See Note)
ISL8840AMBZ 8840 AMBZ
(See Note)
ISL8840AMUZ 40AMZ
(See Note)
ISL8841AABZ
(See Note)
8841 AABZ
-40 to +105 8 Ld MSOP M8.118
-55 to +125 8 Ld SOIC
M8.15
-55 to +125 8 Ld MSOP M8.118
-40 to +105 8 Ld SOIC
M8.15
-55 to +125 8 Ld MSOP M8.118
-40 to +105 8 Ld SOIC
M8.15
ISL8844AAUZ 44AAZ
(See Note)
ISL8844AMBZ 8844 AMBZ
(See Note)
ISL8844AMUZ 44AMZ
(See Note)
ISL8845AABZ
(See Note)
8845 AABZ
-40 to +105 8 Ld MSOP M8.118
-55 to +125 8 Ld SOIC
M8.15
ISL8841AAUZ 41AAZ
(See Note)
ISL8841AMBZ 8841 AMBZ
(See Note)
ISL8841AMUZ 41AMZ
(See Note)
ISL8842AABZ
(See Note)
8842 AABZ
-40 to +105 8 Ld MSOP M8.118
-55 to +125 8 Ld SOIC
M8.15
-55 to +125 8 Ld MSOP M8.118
-40 to +105 8 Ld SOIC
M8.15
-55 to +125 8 Ld MSOP M8.118
-40 to +105 8 Ld SOIC
M8.15
ISL8845AAUZ 45AAZ
(See Note)
ISL8845AMBZ 8845 AMBZ
(See Note)
ISL8845AMUZ 45AMZ
(See Note)
-40 to +105 8 Ld MSOP M8.118
-55 to +125 8 Ld SOIC
M8.15
ISL8842AAUZ 42AAZ
(See Note)
ISL8842AMBZ 8842 AMBZ
(See Note)
ISL8842AMUZ 42AMZ
(See Note)
ISL8843AABZ
(See Note)
8843 AABZ
-40 to +105 8 Ld MSOP M8.118
-55 to +125 8 Ld SOIC
M8.15
-55 to +125 8 Ld MSOP M8.118
-55 to +125 8 Ld MSOP M8.118
-40 to +105 8 Ld SOIC
M8.15
*Add “-T” suffix for tape and reel.
NOTE: Intersil Pb-free plus anneal products employ special Pb-free
material sets; molding compounds/die attach materials and 100%
matte tin plate termination finish, which are RoHS compliant and
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-020.
ISL8843AAUZ 43AAZ
(See Note)
-40 to +105 8 Ld MSOP M8.118
FN6320 Rev 3.00
April 18, 2007
Page 2 of 15
2.5V
4.65V
4.80V
A = 0.5
PWM
COMPARATOR
CS
100mV
+
-
+
-
FB
+
-
ERROR
AMPLIFIER
2R
VF TOTAL = 1.15V
R
1.1V
CLAMP
ONLY
ISL8841A/
ISL8844A/
ISL8845A
Q
T
Q
OUT
S Q
36k
R Q
RESET
DOMINANT
COMP
VREF
100k
2.9V
1.0V
ON
OSCILLATOR
COMPARATOR
<10ns
-
+
8.4mA
ON
CLOCK
150k
RTCT
+
-
FN6320 Rev 3.00
April 18, 2007
Page 3 of 15
Functional Block Diagram
ISL8840A, ISL8841A, ISL8842A, ISL8843A, ISL8844A, ISL8845A
VDD
START/STOP
UV COMPARATOR
+
-
+
-
GND
A
VDD OK
ENABLE
VREF
5.00V
VREF
VREF FAULT
-
+
VREF
UV COMPARATOR
FN6320 Rev 3.00
April 18, 2007
Page 4 of 15
Typical Application - 48V Input Dual Output Flyback
CR5
+3.3V
T1
V
IN
+
R3
C4
CR4
C17
C19
+
C22
+
C20
RETURN
R1
36V TO 75V
C6
C1
C3
Q1
CR6
R16
U2
R17
R19
C14
R18
C21
R21
+1.8V
+ C15
+ C16
ISL8840A, ISL8841A, ISL8842A, ISL8843A, ISL8844A, ISL8845A
C2
C5
CR2
R4
V
IN
-
R22
R27
U3
C13
R15
R20
U4
R26
COMP
CS
FB
VREF
V DD
OUT
RTCT
GND
ISL884xA
R6
CR1
Q3
C12
VR1
C8
R13
R10
C11
FN6320 Rev 3.00
April 18, 2007
Page 5 of 15
Typical Application - Boost Converter
R8
C10
ISL8840A, ISL8841A, ISL8842A, ISL8843A, ISL8844A, ISL8845A
CR1
VIN+
L1
+VOUT
+
C2
C3
Q1
R4
RETURN
R5
C9
C1
R1
R2
U1
COMP
ISL884xA
FB
C4
CS
RTCT
VREF
VDD
OUT
GND
R7
VIN+
C8
R6
R3
C5
C7
C6
VIN-
