参数资料
| 型号： | ISL1801IVZ |
| 厂商： | Intersil |
| 文件页数： | 20/29页 |
| 文件大小： | 0K |
| 描述： | IC CONV SOLAR PWR 48TSSOP |
| 标准包装： | 390 |
| 应用： | 转换器，太阳能 |
| 输入电压： | 9 V ~ 90 V |
| 输出数： | 4 |
| 工作温度： | -40°C ~ 85°C |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 48-TFSOP（0.240"，6.10mm 宽） |
| 供应商设备封装： | 48-TSSOP |
| 包装： | 管件 |
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ISL1801
Whenever WDI enters or exits its disable mode the TIMER pin is
pulled low for 1.5ms.
ISL1801
t 5 : VR2 finishes soft-start and PGOOD2 goes high; reset TIMER
and hold for 1.5ms, then enable the watch-dog function; MCU
starts to run, WDI is floating at VDDREF, TIMER ramps up;
VDDREF
TIME-OUT
0.9*VCC5V
VCC5V
t 6 : MCU sends out the first pulse and the WDI falling edge
(from high to low) resets TIMER for 1.5ms; then TIMER
ramps up;
WDI
40k
R
R
One-
shot
EN
TIMER
t 7 : TIMER is reset for 1.5ms by the WDI rising edge; then
TIMER ramps up;
t 8 : TIMER is reset for 1.5ms by the WDI falling edge; then
TIMER ramps up;
t 9 : TIMER is not reset in time and reaches 90% threshold level;
PGOOD2 is pulled low for 1ms to reset MCU; and TIMER is
0.9*VCC5V
FIGURE 24. WATCH-DOG TIMER LOGIC
It is important to note that the maximum leakage current into
the TIMER pin is 1μA. This leakage current across the pull-up
resistor will set the maximum voltage on the TIMER pin. In order
to assure correct operation, the pull-up resistor from the TIMER
pin to VCC5V should never be more than 200k ? . The voltage drop
for 1μA across 200k ? is 200mV, well below the 90% threshold
value of 5V - (5V * 90%) or 5V - 4.5V = 500mV. This is important
because soft-start is initiated by crossing the 90% of VDD5V
threshold and the watch-dog timeout also depends on crossing
this threshold.
watch-dog timer circuit.
t 0 : The VR1/V OUT1 voltage ramps up to its threshold voltage;
WDI is pulled to VDDREF, which is 0V; TIMER starts to
ramp-up;
t 1 : TIMER reaches the 90% threshold (0.9 * 5V = 4.5V) and
starts to initialize the ISL1801;
t 2 : All preloads are sequentially applied, reset TIMER and hold
it low for 1.5ms;
t 3 : 1.5ms timeout, TIMER starts to ramp up;
t 4 : TIMER voltage reaches 90% threshold, release all preloads
and enable VR2 soft-start;
VOUT1
WDI
4.5V
TIMER
PGOOD2
reset for 1.5ms;
t 10 : PGOOD2 goes back high to exit MCU reset;
t 11 : 1.5ms timeout, TIMER ramps up;
t 12 : TIMER is reset for 1.5ms by the WDI rising edge; then
TIMER ramps up;
t 13 : TIMER is not reset in time and reaches the 90% threshold
level; PGOOD2 is pulled low for 1ms to reset MCU; and
TIMER is reset for 1.5ms;
t 14 : PGOOD2 goes back high to exit MCU reset; then TIMER
ramps up;
t 15 : WDI voltage changes from VDDREF to 0.6*VDDREF; Since
it does not cross the VDDREF/2 threshold no falling edge
signal is generated; TIMER continues ramping up;
t 16 : TIMER is not reset in time, and reaches the 90% threshold
level; PGOOD2 is pulled low for 1ms to reset MCU; and
TIMER is reset for 1.5ms;
t 17 : PGOOD2 goes back high to exit MCU reset; then TIMER
ramps up;
t 18 : TIMER is reset for 1.5ms by the WDI falling edge; then
TIMER ramps up;
t 19 : TIMER is reset by the WDI rising edge; WDI is above
90%*VCC5V threshold level, watch-dog function is
disabled. TIMER ramps up and stays at its high state
however it does not trigger a time-out;
t 20 : WDI drops below the 90%*VCC5V threshold level,
watch-dog function is enabled; TIMER is reset for 1.5ms by
the WDI falling edge; then TIMER ramps up
4.5V
0.6*VDDREF
t 0
t 1
t 2 t 3 t 4 t 5
t 6
t 7
t 8
t 9 t 10 t 11 t 12
t 13 t 14
t 15 t 16 t 17
t 18
t 19
t 20
FIGURE 25. WATCH-DOG TIMER WAVEFORMS
20
FN8259.0
June 29, 2012
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| ISL1801IVZ-T | 功能描述:IC CONV SOLAR PWR 48TSSOP RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - 专用型 系列:- 标准包装:43 系列:- 应用:控制器，Intel VR11 输入电压:5 V ~ 12 V 输出数:1 输出电压:0.5 V ~ 1.6 V 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:48-VFQFN 裸露焊盘 供应商设备封装:48-QFN（7x7） 包装:管件 |
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