参数资料
| 型号： | ISL6740AIVZA |
| 厂商： | Intersil |
| 文件页数： | 9/14页 |
| 文件大小： | 0K |
| 描述： | IC REG CTRLR PWM VM 16-TSSOP |
| 标准包装： | 960 |
| PWM 型： | 电压模式 |
| 输出数： | 1 |
| 频率 - 最大： | 2MHz |
| 占空比： | 100% |
| 电源电压： | 9 V ~ 16 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： | 无 |
| 工作温度： | -40°C ~ 105°C |
| 封装/外壳： | 16-TSSOP（0.173"，4.40mm 宽） |
| 包装： | 管件 |
ISL6740A
V ERROR - The inverting input of the PWM comparator. The error
voltage is applied to this pin to control the duty cycle.
Increasing the signal level increases the duty cycle. The node
may be driven with an external error amplifier or opto-coupler.
The ISL6740A features a built-in soft-start capability. Soft-start
is implemented as a clamp on the error voltage input.
OTS - The non-inverting input to the over temperature
shutdown comparator. The signal input at this pin is compared
to an internal threshold of V REF /2. If the voltage at this pin
exceeds the threshold, the Fault signal is asserted and the
outputs are disabled until the condition clears. There is a
nominal 25μA switched current source used for hysteresis. The
amount of hysteresis is adjustable by varying the source
impedance of the signal into this pin.
OTS may be used to monitor parameters other than
temperature, such as voltage. Any signal for which a high
out-of-bounds monitor is desired may utilize the OTS
comparator.
FAULT - The Fault signal is asserted high whenever the outputs,
OUTA and OUTB, are disabled. This occurs during an over
temperature fault, an input UV fault, a V REF UV fault, or during
an overcurrent or short circuit shutdown fault. Fault can be
used to disable synchronous rectifiers whenever the outputs
are disabled.
Fault is a three-state output and is high impedance during the
soft-start cycle. Adding a pull-up resistor to VREF or a pull-down
resistor to ground determines the state of Fault during
soft-start. This feature allows the designer to use the Fault
signal to enable or disable output synchronous rectifiers during
soft-start.
UV/FF - Undervoltage monitor and voltage feed forward input
pin. A resistor divider between the input source voltage and
GND sets the undervoltage lock-out threshold and provides
voltage sensing for the feed forward compensation circuit.
The signal is compared to an internal 1.00V reference to
detect an undervoltage or inhibit condition. For voltages in
excess of the UV threshold, the signal provides voltage
information to the voltage feed forward function.
CS - This is the input to the current sense comparator. The
overcurrent comparator threshold is set at 0.600V nominal.
The CS pin is shorted to GND at the termination of each output
pulse. Depending on the current sensing source impedance, a
series input resistor may be required due to the delay between
the internal clock and the external power switch. This delay
may allow an overlap such that the CS signal may be
discharged while the current signal is still active. If the current
sense source is low impedance it will cause increased power
dissipation.
Exceeding the overcurrent threshold will start a delayed
shutdown sequence. Once an overcurrent condition is
detected, the soft-start charge current source is disabled. The
soft-start capacitor begins discharging through a 25μA current
source, and if it discharges to less than 4.25V (Sustained
Overcurrent Threshold), a shutdown condition occurs and the
OUTA and OUTB outputs are forced low. When the soft-start
9
voltage reaches 0.27V (Reset Threshold) a soft-start cycle
begins.
An overcurrent condition must be absent for 50 μ s before the
delayed shutdown control resets. If the overcurrent condition
ceases, and an additional 50 μ s period elapses before the
shutdown threshold is reached, no shutdown occurs. The SS
charging current is re-enabled and the soft-start voltage is
allowed to recover.
GND - Reference and power ground for all functions on this
device. Due to high peak currents and high frequency
operation, a low impedance layout is necessary. Ground planes
and short traces are highly recommended.
OUTA and OUTB - Alternate half cycle output stages. Each
output is capable of 0.5A peak currents for driving logic level
power MOSFETs or MOSFET drivers. Each output provides very
low impedance to overshoot and undershoot.
VREF - The 5.00V reference voltage output. +1/-2% tolerance
over line, load and operating temperature. Bypass to GND with
a 0.047μF to 2.2μF ceramic capacitor. Capacitors outside of
this range may cause oscillation.
SS - Connect the soft-start timing capacitor between this pin
and GND to control the duration of soft-start. The value of the
capacitor determines the rate of increase of the duty cycle
during start up, controls the overcurrent shutdown delay, and
the overcurrent and short circuit hiccup restart period.
SCSET - Sets the duty cycle threshold that corresponds to a
short circuit condition. A resistive divider between R TC and
GND, V REF to GND, R TD and GND, or a voltage between 0 and
2V may be used to adjust the SCSET threshold. If using a
resistor divider from either RTC or RTD, the impedance to GND
affects the oscillator timing and should be considered when
determining the oscillator timing components. Connecting
SCSET to GND disables short circuit shutdown and hiccup.
Functional Description
Features
The ISL6740A PWM is an excellent choice for low cost feed
forward voltage mode bridge topologies for applications
requiring accurate duty cycle and deadtime control. With its
many protection and control features, a highly flexible design
with minimal external components is possible. Among its
many features are voltage feed forward compensation,
adjustable soft-start, overcurrent protection, thermal
protection, bidirectional synchronization, fault indication, and
adjustable frequency.
Oscillator
The ISL6740A has an oscillator with a programmable
frequency range to 2MHz, and can be programmed with two
resistors and a capacitor. The use of three timing elements,
R TC , R TD , and C T allows great flexibility and precision when
setting the oscillator frequency.
The switching period is the sum of the timing capacitor charge
and discharge durations. The charge duration is determined by
FN9195.3
February 9, 2012
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| ISL6740AIVZA-T | 功能描述:IC REG CTRLR PWM VM 16-TSSOP 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) |
| ISL6740EVAL1 | 功能描述:EVALUATION BOARD 1 ISL6740 RoHS:否 类别:编程器，开发系统 >> 评估板 - DC/DC 与 AC/DC（离线）SMPS 系列:- 产品培训模块:Obsolescence Mitigation Program 标准包装:1 系列:True Shutdown™ 主要目的:DC/DC，步升 输出及类型:1，非隔离 功率 - 输出:- 输出电压:- 电流 - 输出:1A 输入电压:2.5 V ~ 5.5 V 稳压器拓扑结构:升压 频率 - 开关:3MHz 板类型:完全填充 已供物品:板 已用 IC / 零件:MAX8969 |
| ISL6740EVAL2 | 功能描述:EVALUATION BOARD 2 ISL6740 RoHS:否 类别:编程器，开发系统 >> 过时/停产零件编号 系列:- 标准包装:1 系列:- 传感器类型:CMOS 成像，彩色（RGB） 传感范围:WVGA 接口:I²C 灵敏度:60 fps 电源电压:5.7 V ~ 6.3 V 嵌入式:否 已供物品:成像器板 已用 IC / 零件:KAC-00401 相关产品:4H2099-ND - SENSOR IMAGE WVGA COLOR 48-PQFP4H2094-ND - SENSOR IMAGE WVGA MONO 48-PQFP |
| ISL6740EVAL2Z | 功能描述:EVALUATION BOARD 2 ISL6740 RoHS:是 类别:编程器，开发系统 >> 评估板 - DC/DC 与 AC/DC（离线）SMPS 系列:- 产品培训模块:Obsolescence Mitigation Program 标准包装:1 系列:True Shutdown™ 主要目的:DC/DC，步升 输出及类型:1，非隔离 功率 - 输出:- 输出电压:- 电流 - 输出:1A 输入电压:2.5 V ~ 5.5 V 稳压器拓扑结构:升压 频率 - 开关:3MHz 板类型:完全填充 已供物品:板 已用 IC / 零件:MAX8969 |
| ISL6740EVAL3Z | 制造商:Intersil Corporation 功能描述:ISL6740 EVALUATION BOARD 3 - ROHS COMPLIANT - SOIC - DSL - Bulk 制造商:Intersil Corporation 功能描述:Power Management IC Development Tools ISL6740 EVAL RD 3 ROHS CMPL DSL |
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