9
A resistor (R
OCSET
) programs the over-current trip level for
the PWM converter. As shown in Figure 6, the internal
200礎(chǔ) current sink, I
OCSET
develops a voltage across
R
OCSET
(V
SET
) that is referenced to V
IN
. The DRIVE
signal enables the over-current comparator (OVER-
CURRENT). When the voltage across the upper MOSFET
(V
DS
) exceeds V
SET
, the over-current comparator trips to
set the over-current latch. Both V
SET
and V
DS
are
referenced to V
IN
and a small capacitor across R
OCSET
helps V
OCSET
track the variations of V
IN
due to MOSFET
switching. The over-current function will trip at a peak
inductor current (I
PEAK)
determined by:
The OC trip point varies with MOSFETs r
DS(ON)
temperature variations. To avoid over-current tripping in the
normal operating load range, determine the R
OCSET
resistor from the equation above with:
1. The maximum r
DS(ON)
at the highest junction temperature.
2.  The minimum I
OCSET
from the specification table.
3.  Determine I
PEAK
for I
PEAK
> I
OUT(MAX)
+ (I)/2, where
I is the output inductor ripple current.
For an equation for the ripple current see the section under
component guidelines titled Output Inductor Selection.
OUT1 Voltage Program
The output voltage of the PWM converter is programmed to
discrete levels between 1.3V
DC
and 3.5V
DC
. This output
(OUT1) is designed to supply the core voltage of Intels
advanced microprocessors. The voltage identification (VID)
pins program an internal voltage reference (DACOUT) with a
TTL-compatible 5-bit digital-to-analog converter. The level of
DACOUT also sets the PGOOD and OVP thresholds. Table
1 specifies the DACOUT voltage for the different
combinations of connections on the VID pins. The VID pins
can be left open for a logic 1 input, because they are
internally pulled up to an internal voltage of about 5V by a
10礎(chǔ) current source. Changing the VID inputs during
operation is not recommended and could toggle the PGOOD
signal and exercise the over-voltage protection. 11111 VID
pin combination disables the IC and opens the PGOOD pin.
0A
0V
2V
4V
FIGURE 5. OVER-CURRENT OPERATION
TIME
T1
T2
T3
T0
T4
0V
10V
OVERLOAD
APPLIED
FAULT
REPORTED
COUNT
= 1
COUNT
= 2
COUNT
= 3
I
PEAK
=
I
OCSET
R
OCSET
?/DIV>
r
DS ON
(    )
--------------------------------------------------- -
UGATE
OCSET
PHASE
OVER-
CURRENT
+
-
GATE
CONTROL
VCC
OC
200?/SPAN>A
V
DS
i
D
V
SET
R
OCSET
V
IN
= +5V
OVER-CURRENT TRIP:
I
OCSET
+
+
FIGURE 6. OVER-CURRENT DETECTION
PWM
DRIVE
i
D
r
DS ON
(    )
?/DIV>
I
OCSET
R
OCSET
?/DIV>
>
V
DS
V
SET
>
V
PHASE
V
IN
V
DS
=
V
OCSET
V
IN
V
SET
=
TABLE 1. OUT1 VOLTAGE PROGRAM
PIN NAME
NOMINAL
DACOUT
VOLTAGE
VID4
VID3
VID2
VID1
VID0
0
1
1
1
1
1.30
0
1
1
1
0
1.35
0
1
1
0
1
1.40
0
1
1
0
0
1.45
0
1
0
1
1
1.50
0
1
0
1
0
1.55
0
1
0
0
1
1.60
0
1
0
0
0
1.65
0
0
1
1
1
1.70
0
0
1
1
0
1.75
0
0
1
0
1
1.80
0
0
1
0
0
1.85
0
0
0
1
1
1.90
0
0
0
1
0
1.95
0
0
0
0
1
2.00
0
0
0
0
0
2.05
1
1
1
1
1
0
HIP6021
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
HIP6021CBZ |
功能描述:電壓模式 PWM 控制器 SINGLE PWM & TRPL LINEAR CNTRLR RoHS:否 制造商:Texas Instruments 輸出端數(shù)量:1 拓?fù)浣Y(jié)構(gòu):Buck 輸出電壓:34 V 輸出電流: 開關(guān)頻率: 工作電源電壓:4.5 V to 5.5 V 電源電流:600 uA 最大工作溫度:+ 125 C 最小工作溫度:- 40 C 封裝 / 箱體:WSON-8 封裝:Reel |
HIP6021CBZ-T |
功能描述:電壓模式 PWM 控制器 SINGLE PWM & TRPL LINEAR CNTRLR RoHS:否 制造商:Texas Instruments 輸出端數(shù)量:1 拓?fù)浣Y(jié)構(gòu):Buck 輸出電壓:34 V 輸出電流: 開關(guān)頻率: 工作電源電壓:4.5 V to 5.5 V 電源電流:600 uA 最大工作溫度:+ 125 C 最小工作溫度:- 40 C 封裝 / 箱體:WSON-8 封裝:Reel |
HIP6021EVAL1 |
功能描述:電源管理IC開發(fā)工具 HIP6021 EVAL BRD
RoHS:否 制造商:Maxim Integrated 產(chǎn)品:Evaluation Kits 類型:Battery Management 工具用于評(píng)估:MAX17710GB 輸入電壓: 輸出電壓:1.8 V |
HIP6028 |
制造商:INTERSIL 制造商全稱:Intersil Corporation 功能描述:Advanced PWM and Dual Linear Power Control with Integrated ACPI Support Interface |
HIP6028CB |
制造商:Rochester Electronics LLC 功能描述:- Bulk |