参数资料
| 型号： | ISL62881HRTZ |
| 厂商： | Intersil |
| 文件页数： | 17/35页 |
| 文件大小： | 0K |
| 描述： | IC REG PWM SGL PHASE 28TQFN |
| 标准包装： | 75 |
| 应用： | 控制器，Intel IMVP-6.5? |
| 输入电压： | 5 V ~ 25 V |
| 输出数： | 1 |
| 输出电压： | 0.013 V ~ 1.5 V |
| 工作温度： | -10°C ~ 100°C |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 28-WFQFN 裸露焊盘 |
| 供应商设备封装： | 28-TQFN-EP（4x4） |
| 包装： | 管件 |
第1页第2页第3页第4页第5页第6页第7页第8页第9页第10页第11页第12页第13页第14页第15页第16页当前第17页第18页第19页第20页第21页第22页第23页第24页第25页第26页第27页第28页第29页第30页第31页第32页第33页第34页第35页
ISL62881, ISL62881B
TABLE 3. ISL62881 OCP THRESHOLD AND OVERSHOOT REDUCTION
FUNCTION
Table 4 summarizes the fault protections.
TABLE 4. FAULT PROTECTION SUMMARY
R comp
OCP
OVERSHOOT
FAULT DURATION
MIN
(k Ω )
NOMINAL
(k Ω )
MAX
(k Ω )
THRESHOLD
(μA)
REDUCTION
FUNCTION
FAULT TYPE
BEFORE
PROTECTION
PROTECTION
ACTION
FAULT
RESET
none
none
20
Disabled
Overcurrent
120μs
PWM tri-state, VR_ON
305
205
155
104
78
400
235
165
120
85
410
240
170
130
90
22.67
20.67
18
20
22.67
Enabled
Way-Overcurrent
(2.5xOC)
Overvoltage +200mV
Undervoltage -300mV
Overvoltage 1.55V
<2μs
1ms
Immediately
PGOOD
latched low
Low-side
MOSFET on
toggle or
VDD toggle
VDD toggle
62
45
66
50
68
55
20.67
18
until V core
<0.85V, then
PWM tri-state,
The default OCP threshold is the value when R comp is not
populated. It is recommended to scale the droop current I droop
such that the default OCP threshold gives approximately the
desired OCP level, then use R comp to fine tune the OCP level if
necessary.
For overcurrent condition above 2.5x the OCP level, the PWM
output will immediately shut off and PGOOD will go low to
maximize protection. This protection is also referred to as
PGOOD
latched low.
Current Monitor
The ISL62881 provides the current monitor function. The IMON
pin outputs a high-speed analog current source that is 3 times of
the droop current flowing out of the FB pin. Thus as shown by
Equation 6.
way-overcurrent protection or fast-overcurrent protection, for
short-circuit protections.
I IMON = 3 × I droop
(EQ. 6)
The ISL62881 will declare undervoltage (UV) fault and latch-off if
the output voltage is less than the VID set value by 300mV or
more for 1ms. It’ll turn off the PWM output and de-assert
PGOOD.
The ISL62881 has two levels of overvoltage protections. The first
level of overvoltage protection is referred to as PGOOD
overvoltage protection. If the output voltage exceeds the VID set
value by +200mV for 1ms, the ISL62881 will declare a fault and
de-assert PGOOD.
The ISL62881 takes the same actions for all of the above fault
protections: de-assertion of PGOOD and turn-off of the high-side
and low-side power MOSFETs. Any residual inductor current will
decay through the MOSFET body diodes. These fault conditions
can be reset by bringing VR_ON low or by bringing V DD below the
POR threshold. When VR_ON and V DD return to their high
operating levels, a soft-start will occur.
The second level of overvoltage protection is different. If the
output voltage exceeds 1.55V, the ISL62881 will immediately
declare an OV fault, de-assert PGOOD, and turn on the low-side
power MOSFETs. The low-side power MOSFETs remain on until
the output voltage is pulled down below 0.85V when all power
MOSFETs are turned off. If the output voltage rises above 1.55V
again, the protection process is repeated. This behavior provides
the maximum amount of protection against shorted high-side
power MOSFETs while preventing output ringing below ground.
Resetting VR_ON cannot clear the 1.55V OVP. Only resetting V DD
will clear it. The 1.55V OVP is active all the time when the
controller is enabled, even if one of the other faults have been
declared. This ensures that the processor is protected against
high-side power MOSFET leakage while the MOSFETs are
commanded off.
17
As Figures 1 and 2 show, a resistor R imon is connected to the
IMON pin to convert the IMON pin current to voltage. A capacitor
can be paralleled with R imon to filter the voltage information. The
IMVP-6.5 ? specification requires that the IMON voltage
information be referenced to VSS SENSE .
The IMON pin voltage range is 0V to 1.1V. A clamp circuit
prevents the IMON pin voltage from going above 1.1V.
Adaptive Body Diode Conduction Time
Reduction
In DCM, the controller turns off the low-side MOSFET when the
inductor current approaches zero. During on-time of the low-side
MOSFET, phase voltage is negative and the amount is the
MOSFET R DS(ON) voltage drop, which is proportional to the
inductor current. A phase comparator inside the controller
monitors the phase voltage during on-time of the low-side
MOSFET and compares it with a threshold to determine the
zero-crossing point of the inductor current. If the inductor current
has not reached zero when the low-side MOSFET turns off, it’ll
flow through the low-side MOSFET body diode, causing the phase
node to have a larger voltage drop until it decays to zero. If the
inductor current has crossed zero and reversed the direction
when the low-side MOSFET turns off, it’ll flow through the
high-side MOSFET body diode, causing the phase node to have a
spike until it decays to zero. The controller continues monitoring
the phase voltage after turning off the low-side MOSFET and adjusts
the phase comparator threshold voltage accordingly in iterative steps
such that the low-side MOSFET body diode conducts for
approximately 40ns to minimize the body diode-related loss.
FN6924.3
June 16, 2011
相关PDF资料 |
PDF描述 |
|---|---|
| ISL62882IRTZ | IC REG PWM 2PHASE BUCK 40TQFN |
| ISL62883IRTZ | IC REG PWM 3PHASE BUCK 40TQFN |
| ISL6292BCRZ | IC CHARGER LI-ION 4.2V 4X4 16QFN |
| ISL6294IBZ | IC CHRGR LI-ION SGL 8-SOIC |
| ISL6306IRZ | IC REG CTRLR BUCK PWM VM 40-QFN |
相关代理商/技术参数 |
参数描述 |
|---|---|
| ISL62881HRTZ-T | 功能描述:直流/直流开关调节器 1 PHS PWM BUCKG FOR MICROPROCESR PWR SUP RoHS:否 制造商:International Rectifier 最大输入电压:21 V 开关频率:1.5 MHz 输出电压:0.5 V to 0.86 V 输出电流:4 A 输出端数量: 最大工作温度: 安装风格:SMD/SMT 封装 / 箱体:PQFN 4 x 5 |
| ISL62882 | 制造商:INTERSIL 制造商全称:Intersil Corporation 功能描述:Multiphase PWM Regulator for IMVP-6.5 Mobile CPUs and GPUs |
| ISL62882B | 制造商:INTERSIL 制造商全称:Intersil Corporation 功能描述:Multiphase PWM Regulator for IMVP-6.5 Mobile CPUs and GPUs |
| ISL62882BHRTZ | 功能描述:直流/直流开关调节器 2 PHS PWM BUCKG FOR MICROPROC PWR SUP RoHS:否 制造商:International Rectifier 最大输入电压:21 V 开关频率:1.5 MHz 输出电压:0.5 V to 0.86 V 输出电流:4 A 输出端数量: 最大工作温度: 安装风格:SMD/SMT 封装 / 箱体:PQFN 4 x 5 |
| ISL62882BHRTZR5411 | 制造商:Intersil Corporation 功能描述: |
发布紧急采购，3分钟左右您将得到回复。