ISL78229 Datasheet, PDF (61/71 Pages) Intersil Corporation – 2-Phase Boost Controller with Drivers

ISL78229
BIT NUMBER
8
9
15:10
FAULT NAME
PLLCOMP_SHORT
PLL_LOCK
Not used
DEFAULT VALUE
Set by the
HIC/LATCH pin
Set by the
HIC/LATCH pin
000000
MEANING
PLLCOMP_SHORT fault (PLLCOMP_PIN >1.7V) protection response is
Hiccup when bit = 1, and Latch-off when bit = 0
PLL loop fault (detect the minimum frequency of 37kHz as typical)
protection response is Hiccup when bit = 1, and Latch-off when bit = 0
Not used
VOUT_OV_FAULT_LIMIT (D3h)
Definition: Set/Read the output overvoltage fault threshold. The output overvoltage fault is generated by a comparator comparing the
FB pin voltage with VOUT_OV threshold which has setting options based on percentage of the VREF_DAC reference voltage. This
command set OV threshold with 8 options ranging from 105% to 125% of the reference voltage VREF_DAC. The default is set at 120%
of VREF_DAC.
Equivalently the V_OUT overvoltage threshold is set at the same percentage of V_OUT target voltage (set by VREF_DAC) since the device
uses the same FB voltage to regulate the output voltage with the same resistor divider between V_OUT and the FB pin. For example, at
default, the V_OUT overvoltage threshold is set at 120% of V_{OUT_TARGET}. According to Equation 2 on page 26, the default V_OUT
overvoltage threshold can be calculated using Equation 31. Other threshold options can be calculated using Equation 31 with 1.2
replaced with other percentage options.
VOUT_OVdefault
=
1.2

V_REFDAC



1

+
RR_{-----FF----BB----21-}
(EQ. 31)
This fault detection is active at the beginning of soft-start (t₅ as shown in Figure 67 on page 30).
When OV fault occurs, the corresponding bit in the FAULT_STATUS register is set to 1 and the SALERT pin is pulled low. The OV fault
protection response is by default active and the fault response is either Hiccup or Latch-off determined by the corresponding bit of
FAULT_RESPONSE register of which default value is determined by the HIC/LATCH pin.
For related description, refer to “Output Overvoltage Fault” on page 36, Table 3 on page 41 and the “PMBus™ Command Summary” on
page 43 to deactivate this fault and configure the fault response.
Data Length in Bytes: 1
Data Format: Bit Field
Type: R/W
Protectable: Yes
Default Value: 06h, which equals to 0000_0110b, meaning 120% of VREF_DAC
Units:%
COMMAND
Format
Bit Position
Access
Function
Default Value
7
R/W
0
6
R/W
0
5
R/W
0
OVP_SET (D3h)
Bit Field
4
3
R/W
R/W
See Following Table
0
0
2
R/W
1
1
R/W
1
0
R/W
0
BITS 7:3
(NOT USED)
Not Used
Not Used
Not Used
Not Used
Not Used
Not Used
Not Used
Not Used
BITS 2:0
000
001
010
011
100
101
110
111
PERCENTAGE OF VREF_DAC (%)
105
107.5
110
112.5
115
117.5
120
125
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FN8656.3
February 12, 2016