参数资料
| 型号： | ISL8121IRZ |
| 厂商： | Intersil |
| 文件页数： | 9/26页 |
| 文件大小： | 0K |
| 描述： | IC REG CTRLR BUCK PWM VM 24-QFN |
| 标准包装： | 75 |
| PWM 型： | 电压模式 |
| 输出数： | 1 |
| 频率 - 最大： | 2MHz |
| 占空比： | 66% |
| 电源电压： | 4.9 V ~ 5.5 V |
| 降压： | 是 |
| 升压： | 无 |
| 回扫： | 无 |
| 反相： | 无 |
| 倍增器： | 无 |
| 除法器： | 无 |
| Cuk： | 无 |
| 隔离： | 无 |
| 工作温度： | -40°C ~ 85°C |
| 封装/外壳： | 24-VFQFN 裸露焊盘 |
| 包装： | 管件 |
ISL8121
ISL8121
V IN
REFERENCE
OSCILLATOR
UG1
COMP
Σ
PWM
CIRCUIT
HALF-BRIDGE
DRIVE
PHASE1
LG1
R2
C1
Σ
PWM
CIRCUIT
HALF-BRIDGE
DRIVE
R ISEN1
L1
V OUT
FB
Σ
CURRENT
SENSE
ISEN1
V IN
L2
C OUT
R1
AVERAGE
UG2
PHASE2
VDIFF
VSEN+
VSEN-
Σ
CURRENT
SENSE
LG2
ISEN2
R ISEN2
FIGURE 2. SIMPLIFIED BLOCK DIAGRAM OF THE ISL8121 VOLTAGE AND CURRENT CONTROL LOOPS
Operation
Figure 2 shows a simplified diagram of the voltage
regulation and current loops. The voltage loop is used to
precisely regulate the output voltage, while the current
feedback is used to balance the output currents, I L1 and
I L2 , of the two power channels.
VOLTAGE LOOP
Feedback from the output voltage is fed via the on-board
differential amplifier and applied via resistor R1 to the
inverting input of the Error Amplifier. The signal
generated by the error amplifier is summed up with the
current correction error signal and applied to the positive
inputs of the PWM circuit comparators. Out-of-phase
sawtooth signals are applied to the two PWM
comparators inverting inputs. Increasing error amplifier
voltage results in increased duty cycle. This increased
duty cycle signal is passed to the output drivers with no
phase reversal to drive the external MOSFETs. Increased
duty cycle, translating to increased ON-time for the
upper MOSFET transistor, results in increased output
voltage, compensating for the low output voltage which
lead to the increase in the error signal in the first place.
CURRENT LOOP
The current control loop is only used to finely adjust the
individual channel duty cycle, in order to balance the
current carried by each phase. The information used for
9
this control is the voltage that is developed across
r DS(ON) of each lower MOSFET, while they are
conducting. A resistor converts and scales the voltage
across each MOSFET to a current that is applied to the
current sensing circuits within the ISL8121. Output from
these sensing circuits is averaged and used to compute a
current error signal. Each PWM channel receives a
current signal proportional to the difference between the
average sensed current and the individual channel
current. When a PWM channel’s current is greater than
the average current, the signal applied via the summing
correction circuit to the PWM comparator reduces the
output pulse width (duty cycle) of the comparator to
compensate for the detected above average current in
the respective channel.
MULTI-PHASE POWER CONVERSION
Multi-phase power conversion provides a cost-effective
power solution when load currents are no longer easily
supported by single-phase converters. Although its
greater complexity presents additional technical
challenges, the multi-phase approach offers advantages
with improved response time, superior ripple
cancellation, and thermal distribution.
INTERLEAVING
The switching of each channel in a ISL8121-based
converter is timed to be symmetrically out of phase with
the other channel. As a result, the two-phase converter
FN6352.2
October 27, 2009
相关PDF资料 |
PDF描述 |
|---|---|
| ISL8126IRZ | IC REG CTRLR BUCK PWM VM 32-QFN |
| ISL8130IAZ | IC REG CTRLR BST FLYBK VM 20QSOP |
| ISL85001IRZ-T | IC REG BUCK ADJ 1A 12DFN |
| ISL8500IRZ-T | IC REG BUCK ADJ 2A 12DFN |
| ISL8502AIRZ | IC REG BUCK SYNC ADJ 2A 24QFN |
相关代理商/技术参数 |
参数描述 |
|---|---|
| ISL8121IRZ-T | 功能描述:IC REG CTRLR BUCK PWM VM 24-QFN RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 切换控制器 系列:- 产品培训模块:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 标准包装:2,500 系列:- PWM 型:电流模式 输出数:1 频率 - 最大:275kHz 占空比:50% 电源电压:18 V ~ 110 V 降压:无 升压:无 回扫:无 反相:无 倍增器:无 除法器:无 Cuk:无 隔离:是 工作温度:-40°C ~ 85°C 封装/外壳:8-SOIC（0.154"，3.90mm 宽） 包装:带卷 (TR) |
| ISL8121IRZ-TR5453 | 制造商:Intersil Corporation 功能描述:STD. ISL8121IRZ-T WITH GOLD BOND WIRE ONLY - Tape and Reel |
| ISL8126 | 制造商:INTERSIL 制造商全称:Intersil Corporation 功能描述:Dual/n-Phase Buck PWM Controller with Integrated Drivers |
| ISL8126CRZ | 功能描述:IC REG CTRLR BUCK PWM VM 32-QFN RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 切换控制器 系列:- 产品培训模块:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 标准包装:2,500 系列:- PWM 型:电流模式 输出数:1 频率 - 最大:275kHz 占空比:50% 电源电压:18 V ~ 110 V 降压:无 升压:无 回扫:无 反相:无 倍增器:无 除法器:无 Cuk:无 隔离:是 工作温度:-40°C ~ 85°C 封装/外壳:8-SOIC（0.154"，3.90mm 宽） 包装:带卷 (TR) |
| ISL8126CRZ-T | 功能描述:IC REG CTRLR BUCK PWM VM 32-QFN RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 切换控制器 系列:- 产品培训模块:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 标准包装:2,500 系列:- PWM 型:电流模式 输出数:1 频率 - 最大:275kHz 占空比:50% 电源电压:18 V ~ 110 V 降压:无 升压:无 回扫:无 反相:无 倍增器:无 除法器:无 Cuk:无 隔离:是 工作温度:-40°C ~ 85°C 封装/外壳:8-SOIC（0.154"，3.90mm 宽） 包装:带卷 (TR) |
发布紧急采购，3分钟左右您将得到回复。