- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄383151 > ISL6523A (Intersil Corporation) Adjustable Precision Shunt Regulator 3-SOT-89 0 to 70 PDF資料下載
參數(shù)資料
| 型號： | ISL6523A |
| 廠商： | Intersil Corporation |
| 英文描述： | Adjustable Precision Shunt Regulator 3-SOT-89 0 to 70 |
| 中文描述： | VRM8.5雙雙PWM和線性電源系統(tǒng)控制器 |
| 文件頁數(shù)： | 8/16頁 |
| 文件大?。?/td> | 408K |
| 代理商： | ISL6523A |
8
and the soft-start signals (SS13, SS24). Window
comparators monitor the SS pins and indicate when the
respective C
SS
pins are fully charged to above 4.0V (UP
signals). An under-voltage on either linear output (VSEN3 or
VSEN4) is ignored until the respective UP signal goes high.
This allows V
OUT3
and V
OUT4
to increase without fault at
start-up. Following an overcurrent event (OC1, OC2, or UV3
event), bringing the SS24 pin below 0.8V resets the
overcurrent latch and generates a soft-started ramp-up of
the outputs 1, 2, and 3.
OUT1 Overvoltage Protection
During operation, a short across the synchronous PWM
upper MOSFET (Q1) causes V
OUT1
to increase. When the
output exceeds the over-voltage threshold of 120% of
DACOUT, the over-voltage comparator trips to set the fault
latch and turns the lower MOSFET (Q2) on as needed to
regulate the output voltage to the 120% threshold. This
operation typically results in the blow of the input fuse,
subsequent discharge of V
OUT1
.
A separate over-voltage circuit provides protection during
the initial application of power. For voltages on the VCC pin
below the power-on reset (and above ~4V), the output level
is monitored for voltages above 1.3V. Should VSEN1 exceed
this level, the lower MOSFET, Q2, is driven on.
Overcurrent Protection
All outputs are protected against excessive overcurrents.
Both PWM controllers use the upper MOSFET’s on-
resistance, r
DS(ON)
to monitor the current for protection
against shorted outputs. Both linear regulators monitor their
respective VSEN pins for under-voltage to protect against
excessive currents.
Figure 7 illustrates the overcurrent protection with an overload
on OUT2. The overload is applied at T0 and the current
increases through the inductor (L
OUT2
). At time T1, the OC2
comparator trips when the voltage across Q3 (i
D
r
DS(ON)
)
exceeds the level programmed by R
OCSET
. This inhibits
outputs 1, 2, and 3, discharges soft-start capacitor C
SS24
with
28
μ
A current sink, and increments the counter. Soft-start
capacitor C
SS13
is quickly discharged. C
SS24
recharges at T2
and initiates a soft-start cycle with the error amplifiers clamped
by soft-start. With OUT2 still overloaded, the inductor current
increases to trip the overcurrent comparator. Again, this
inhibits the outputs, but the soft-start voltage continues
increasing to above 4.0V before discharging. The counter
increments to 2. The soft-start cycle repeats at T3 and trips
the overcurrent comparator. The SS pin voltage increases to
above 4.0V at T4 and the counter increments to 3. This sets
the fault latch to disable the converter.
The PWM1 controller operates in the same way as PWM2 to
overcurrent faults. Additionally, the two linear controllers
monitor the VSEN pins for under-voltage. Should excessive
currents cause VSEN3 or VSEN4 to fall below the linear
under-voltage threshold, the respective UV signals set the
OC latch or the FAULT latch, providing respective C
SS
capacitors are fully charged. Blanking the UV signals during the
C
SS
charge interval allows the linear outputs to build above
the under-voltage threshold during normal operation. Cycling
the bias input power off then on resets the counter and the
fault latch.
Resistors (R
OCSET1
and R
OCSET2
) program the overcurrent
trip levels for each PWM converter. As shown in Figure 8, the
internal 200
μ
A current sink (I
OCSET
) develops a voltage across
R
OCSET
(V
SET
) that is referenced to V
IN
. The DRIVE signal
enables the overcurrent comparator (OVERCURRENT1 or
OVERCURRENT2). When the voltage across the upper
MOSFET (V
DS(ON)
) exceeds V
SET
, the overcurrent
comparator trips to set the overcurrent 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 overcurrent function will trip at a peak
inductor current (I
PEAK)
determined by:
The OC trip point varies with MOSFET’s rDS(ON)
temperature variations. To avoid overcurrent tripping in the
normal operating load range, determine the ROCSET
resistor value 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’.
FIGURE 7. OVERCURRENT OPERATION
S
0A
0V
2V
4V
TIME
T1
T2
T3
T0
T4
F
0
1
OVERLOAD
APPLIED
CHIP
DISABLED
COUNT
= 1
COUNT
= 2
COUNT
= 3
L
S
I
PEAK
=
I
---------------------------------------------------
R
×
DS ON
)
ISL6523A
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| ISL6523 | Adjustable Precision Shunt Regulator 3-SOT-23 0 to 70 |
| ISL6523ACB | Adjustable Precision Shunt Regulator 3-SOT-89 0 to 70 |
| ISL6523CB | Adjustable Precision Shunt Regulator 5-SOT-23 -40 to 85 |
| ISL6523CBZ | Adjustable Precision Shunt Regulator 5-SOT-23 -40 to 85 |
| ISL6523CBZ-T | VRM8.5 Dual PWM and Dual Linear Power System Controller |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| ISL6523ACB | 制造商:Rochester Electronics LLC 功能描述:- Bulk |
| ISL6523CB | 功能描述:IC CTRLR VRM8.5 PWM DUAL 28-SOIC RoHS:否 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - 專用型 系列:- 產(chǎn)品培訓模塊:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 標準包裝:2,000 系列:- 應用:電源，ICERA E400，E450 輸入電壓:4.1 V ~ 5.5 V 輸出數(shù):10 輸出電壓:可編程 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:42-WFBGA，WLCSP 供應商設備封裝:42-WLP 包裝:帶卷 (TR) |
| ISL6523CB-T | 功能描述:IC CTRLR VRM8.5 PWM DUAL 28-SOIC RoHS:否 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - 專用型 系列:- 產(chǎn)品培訓模塊:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 標準包裝:2,000 系列:- 應用:電源，ICERA E400，E450 輸入電壓:4.1 V ~ 5.5 V 輸出數(shù):10 輸出電壓:可編程 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:42-WFBGA，WLCSP 供應商設備封裝:42-WLP 包裝:帶卷 (TR) |
| ISL6523CBZ | 功能描述:IC CTRLR VRM8.5 PWM DUAL 28-SOIC RoHS:是 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - 專用型 系列:- 標準包裝:43 系列:- 應用:控制器，Intel VR11 輸入電壓:5 V ~ 12 V 輸出數(shù):1 輸出電壓:0.5 V ~ 1.6 V 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:48-VFQFN 裸露焊盤 供應商設備封裝:48-QFN（7x7） 包裝:管件 |
| ISL6523CBZ-T | 功能描述:IC CTRLR VRM8.5 PWM DUAL 28-SOIC RoHS:是 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - 專用型 系列:- 標準包裝:43 系列:- 應用:控制器，Intel VR11 輸入電壓:5 V ~ 12 V 輸出數(shù):1 輸出電壓:0.5 V ~ 1.6 V 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:48-VFQFN 裸露焊盤 供應商設備封裝:48-QFN（7x7） 包裝:管件 |
發(fā)布緊急采購，3分鐘左右您將得到回復。