ISL62871HRUZ-T Intersil, ISL62871HRUZ-T Datasheet - Page 12

• Manufacturer Part Number: ISL62871HRUZ-T
• Description: IC CTRLR DC/DC PWM 16-TQFN
• Manufacturer: Intersil

Specifications of ISL62871HRUZ-T

• Pwm Type: Controller
• Number Of Outputs: 1
• Frequency - Max: 330kHz
• Duty Cycle: 100%
• Voltage - Supply: 3.3 V ~ 25 V
• Buck: Yes
• Boost: No
• Flyback: No
• Inverting: No
• Doubler: No
• Divider: No
• Cuk: No
• Isolated: No
• Operating Temperature: -10°C ~ 100°C
• Package / Case: 16-UTQFN (16-µTQFN)
• Frequency-max: 330kHz
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

The ISL62872 V
The ISL62872 V
The ISL62872 V
The ISL62872 V
Component Selection for ISL62871 Setpoint
Voltage Programming Resistors
First, determine the attenuation factor K. Next, assign an
initial value to R
R
V
V
V
V
SET2
SET3
SET4
SET1
SET1
FIGURE 8. ISL62872 VOLTAGE PROGRAMMING CIRCUIT
V
OUT
STATE
VID0
1
0
=
=
=
using Equation 13.
=
V
V
V
V
R
REF
REF
REF
REF
FB
TABLE 2. ISL62871 VID TRUTH TABLE
⋅
⋅
⋅
SET2
⎛
⎜
⎝
⎛
⎜
⎝
⎛
⎜
⎝
SET1
SET2
SET3
SET4
1
1
1
+
+
+
CLOSE
SREF
SET0
SET1
SET2
-------------------------------------------------------------------- -
R
R
------------------------------------------- -
R
R
-------------------------------------------------------------------- -
SW0
SW1
FB
of approximately 150kΩ then calculate
setpoint is written as Equation 9:
setpoint is written as Equation 10:
SET2
setpoint is written as Equation 11:
SET1
SET3
setpoint is written as Equation 12:
SET1
+
+
+
+
12
R
R
R
R
R
R
SET1
SET3
SET2
SET4
SET2
SET4
RESULT
V
V
V
⎞
⎟
⎠
+
+
SREF
SET1
SET2
−
+
R
R
EA
SW0
SW1
SW2
SW3
SET4
SET3
V
SET
+
−
⎞
⎟
⎠
⎞
⎟
⎠
500mV
V
V
COMP
REF
V
V
V
ISL62871, ISL62872
OUT1
OUT2
OUT
(EQ. 10)
(EQ. 11)
(EQ. 12)
(EQ. 9)
The equation for the value of R
Equation 13:
The sum of R
be approximately 300kΩ as shown in Equation 14 otherwise
adjust the value of R
Equations 15 and 16 give the specific V
for the ISL62871 setpoint reference voltages.
The ISL62871 V
The ISL62871 V
R
R
V
V
SET1
SET2
SET1
SET1
V
FIGURE 9. ISL62871 VOLTAGE PROGRAMMING CIRCUIT
OUT
+
=
=
=
R
R
V
V
R
SET2
FB
REF
REF
SET2
SET1
⋅
≅
SET1
SET2
⎛
⎜
⎝
⋅
300kΩ
1
⎛
⎜
⎝
KV
---------------------- - 1
and R
+
SREF
SET0
V
SET2
R
------------------
R
REF
SET2
FB
setpoint is written as Equation 15:
setpoint is written as Equation 16:
SET1
SET2
SET2
and repeat the calculations.
–
⎞
⎟
⎠
⎞
⎟
⎠
programming resistors should
SET1
is written as
−
+
EA
SW0
SW1
V
SET
SET
+
−
gain equations
V
V
COMP
REF
August 14, 2008
(EQ. 13)
(EQ. 14)
(EQ. 16)
(EQ. 15)
FN6707.0