- 您现在的位置：买卖IC网 > PDF目录13603 > ISL8016IRAJZ-T (Intersil)IC REG BUCK SYNC ADJ 6A 20QFN PDF资料下载
参数资料
| 型号： | ISL8016IRAJZ-T |
| 厂商： | Intersil |
| 文件页数： | 15/22页 |
| 文件大小： | 0K |
| 描述： | IC REG BUCK SYNC ADJ 6A 20QFN |
| 产品培训模块： | Solutions for Industrial Control Applications |
| 标准包装： | 6,000 |
| 类型： | 降压（降压） |
| 输出类型： | 可调式 |
| 输出数： | 1 |
| 输出电压： | 0.6 V ~ 5.5 V |
| 输入电压： | 2.7 V ~ 5.5 V |
| PWM 型： | 电流模式 |
| 频率 - 开关： | 525kHz ~ 3.9MHz |
| 电流 - 输出： | 6A |
| 同步整流器： | 是 |
| 工作温度： | -40°C ~ 85°C |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 20-VFQFN 裸露焊盘 |
| 包装： | 带卷 (TR) |
| 供应商设备封装： | 20-QFN（3x4） |
ISL8016
Theory of Operation
The ISL8016 is a step-down switching regulator optimized for
battery-powered handheld applications. The regulator operates at
1MHz fixed default switching frequency when FS is connected to VIN.
By connecting a resistor from FS to SGND, the operating frequency
may be adjusted from 500kHz to 4MHz. Unless forced, PWM is
chosen (SYNCIN pulled HI), the regulator will allow PFM operation
and reduce switching frequency at light loading to maximize
efficiency. In this condition, no load quiescent is typically 70μA.
PWM Control Scheme
Pulling the SYNCIN high (>0.8V) forces the converter into PWM
mode, regardless of output current. The ISL8016 employs the
current-mode pulse-width modulation (PWM) control scheme for fast
transient response and pulse-by-pulse current limiting. Figure 4
shows the block diagram. The current loop consists of the oscillator,
the PWM comparator, current sensing circuit and the slope
compensation for the current loop stability. The slope compensation
is 360mV/Ts. Current sense resistance, Rt, is typically 0.138V/A. The
control reference for the current loop comes from the error
amplifier's (EAMP) output.
The PWM operation is initialized by the clock from the oscillator.
The P-Channel MOSFET is turned on at the beginning of a PWM
cycle and the current in the MOSFET starts to ramp up. When the
sum of the current amplifier CSA and the slope compensation
reaches the control reference of the current loop, the PWM
comparator EAMP output sends a signal to the PWM logic to turn
off the P-FET and turn on the N-Channel MOSFET. The N-FET stays
on until the end of the PWM cycle. Figure 33 shows the typical
operating waveforms during the PWM operation. The dotted lines
illustrate the sum of the slope compensation ramp and the
current-sense amplifier’s CSA output.
The output voltage is regulated by controlling the V EAMP voltage
to the current loop. The bandgap circuit outputs a 0.6V reference
voltage to the voltage loop. The feedback signal comes from the
VFB pin. The soft-start block only affects the operation during the
start-up and will be discussed separately. The error amplifier is a
transconductance amplifier that converts the voltage error signal
to a current output. The voltage loop is internally compensated
with the 55pF and 168k ? RC network. The maximum EAMP
voltage output is precisely clamped to 2.4V.
V EAMP
V CSA
DUTY
CYCLE
I L
V OUT
FIGURE 33. PWM OPERATION WAVEFORMS
SKIP Mode
Pulling the SYNCIN pin LO (<0.4V) forces the converter into PFM
mode. The ISL8016 enters a pulse-skipping mode at light load to
minimize the switching loss by reducing the switching frequency.
Figure 34 illustrates the skip-mode operation. A zero-cross
sensing circuit shown in Figure 4 monitors the N-FET current for
zero crossing. When 8 consecutive cycles of the inductor current
crossing zero are detected, the regulator enters the skip mode.
During the eight detecting cycles, the current in the inductor is
allowed to become negative. The counter is reset to zero when
the current in any cycle does not cross zero.
Once the skip mode is entered, the pulse modulation starts being
controlled by the SKIP comparator shown in Figure 34. Each pulse
cycle is still synchronized by the PWM clock. The P-FET is turned on
at the clock's rising edge and turned off when the output is higher
than 1.5% of the nominal regulation or when its current reaches the
peak Skip current limit value. Then the inductor current is
discharging to 0A and stays at zero. The internal clock is disabled.
The output voltage reduces gradually due to the load current
discharging the output capacitor. When the output voltage drops to
the nominal voltage, the P-FET will be turned on again at the rising
edge of the internal clock as it repeats the previous operations.
The regulator resumes normal PWM mode operation when the
output voltage drops 1.5% below the nominal voltage.
SYNCOUT
CLOCK
I L
0
V OUT
PWM
0.8V
8 CYCLES
NOMINAL +1.5%
PFM
PFM CURRENT LIMIT
LOAD CURRENT
NOMINAL
NOMINAL -1.5%
PWM
FIGURE 34. SKIP MODE OPERATION WAVEFORMS
15
FN7616.1
May 5, 2011
相关PDF资料 |
PDF描述 |
|---|---|
| SCRH123-6R2 | INDUCTOR SMD 6.2UH 6.70A 100KHZ |
| ISL8016IR33Z-T | IC REG BUCK SYNC 3.3V 6A 20QFN |
| VI-J50-EX-F2 | CONVERTER MOD DC/DC 5V 75W |
| ISL8016IR25Z-T | IC REG BUCK SYNC 2.5V 6A 20QFN |
| ISL8016IR18Z-T | IC REG BUCK SYNC 1.8V 6A 20QFN |
相关代理商/技术参数 |
参数描述 |
|---|---|
| ISL8016IRAJZ-T7A | 功能描述:直流/直流开关转换器 6A ADJ VOUT LW QUIES CENT CUR SYNC BUCK RoHS:否 制造商:STMicroelectronics 最大输入电压:4.5 V 开关频率:1.5 MHz 输出电压:4.6 V 输出电流:250 mA 输出端数量:2 最大工作温度:+ 85 C 安装风格:SMD/SMT |
| ISL8022 | 制造商:INTERSIL 制造商全称:Intersil Corporation 功能描述:Dual 2A/1.7A Low Quiescent Current 2.25MHz High Efficiency Synchronous |
| ISL8022EVAL1Z | 功能描述:EVAL BOARD 1 FOR ISL8022 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 |
| ISL8022EVAL2Z | 功能描述:EVAL BOARD 2 FOR ISL8023 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 |
| ISL8022IRZ | 功能描述:直流/直流开关调节器 DL CH 2 25MHZ 2 0 A & 1 7ASYNCHG 4X3 1 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 |
发布紧急采购，3分钟左右您将得到回复。