ISL70002SEH Datasheet, PDF (3/23 Pages) Intersil Corporation – Rad Hard and SEE Hard 12A Synchronous Buck Regulator with Multi-Phase Current Sharing

Pin Configuration
ISL70002SEH
ISL70002SEH
(64 LD CQFP)
TOP VIEW
FB
ISHA
ISHREFA
ISHB
ISHREFB
ISHC
ISHREFC
AVDD
AGND
DGND
DVDD
SS
PGOOD
ISHCOM
ISHSL
ISHEN
64 63 62 61 60 59 58 57 56 55 54 53 52 51 50 49
1
48
2
47
3
46
4
45
5
44
6
43
7
42
8
41
9
40
10
39
11
38
12
37
13
36
14
35
15
34
16
33
17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32
LX3
PGND3
PGND4
LX4
PVIN4
PVIN5
LX5
PGND5
PGND6
LX6
PVIN6
PVIN7
LX7
PGND7
PGND8
LX8
Pin Descriptions
PIN NUMBER
1
PIN NAME
FB
2, 4, 6
ISHA/B/C
DESCRIPTION
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 1:
V_OUT = V_REF ⋅ [1 + (R_T ⁄ R_B)]
(EQ. 1)
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.
If using current share, tie FB of the Master to FB of the Slave.
If configured as a current share Master (ISHSL = DGND, ISHEN = DVDD), the ISHA/B/C pins are outputs that
provides a current equal to 25 times the redundant A/B/C error amp output currents plus ISHREFA/B/C
(nominally 100µA each). If configured as a current share Slave (ISHSL = DVDD, ISHEN = DVDD), the ISHA/B/C
pins are inputs that become the Slave’s redundant A/B/C error amp output current. If using current share, tie
ISHA/B/C of the Master to ISHA/B/C of the Slave. If not using current share, tie ISHA/B/C to DVDD. ISHA/B/C
are tri-stated prior to a valid POR and when ISHEN = DGND.
3
FN8264.1
April 5, 2012