BD3004HFP-TR Rohm Semiconductor, BD3004HFP-TR Datasheet - Page 5

• Manufacturer Part Number: BD3004HFP-TR
• Description: IC REG WATCHDOG TIMER HRP7
• Manufacturer: Rohm Semiconductor

Specifications of BD3004HFP-TR

• Function: Current Regulator
• Accuracy: ±2%
• Voltage - Input: 5.5 ~ 36 V
• Current - Output: 500mA
• Operating Temperature: -40°C ~ 125°C
• Mounting Type: Surface Mount
• Package / Case: HRP-7
• Threshold Voltage: 4.1V
• No. Of Supervisors / Monitors: 1
• Supply Voltage Range: 5.5V To 36V
• Supply Current: 80µA
• Digital Ic Case Style: HRP
• No. Of Pins: 7
• Operating Temperature Range: -40°C To +125°C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Sensing Method: -
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant

● Detection voltage adjustment
Timing chart
Explanation
(1) When the output voltage (VOUT) reaches 1.0 V, the reset pin voltage (RESET) will switch to low level.
(2) When VOUT reaches or exceeds the reset clear voltage (VdetH), the external capacitor connected to the CT pin will begin to charge.
(3) The watchdog timer operates when RESET rises.
(4) When VCT reaches the lower switching threshold voltage (VthL), the CT pin switches from discharging to charging, and RESET
(5) The CT pin state switches from charge to discharge when VCT reaches VthH, and RESET switches from low to high.
(6) The CT pin state may not switche from charge to discharge when the CLK input pulse width (TWCLK) is short.
(7) When a pulse (positive edge trigger) of at least 500 ns is input to the CLK pin while the CT pin is discharging, VCT switches from
(8) Watchdog timer operation is forced off when the INH pin switches to high. At that time, only the watchdog timer will be turned off, and
(9) The watchdog timer function turns on when the INH pin switches to low. At that time, the external capacitor on the CT pin will be
(10) RESET switches from high to low when OUT falls to the RESET detection voltage (VDET) or lower.
(11) When VOUT falls to 0 V, the RESET signal stays low until VOUT reaches 1.0 V
RESET
VOUT
VINH
R4
R3
Vcc
VCT
CLK
When the CT pin voltage (VCT) reaches the upper switching threshold voltage (VthH), RESET will maintain a low-level signal. When
VCT reaches the VthH voltage, RESET will switch from low to high level. The time from VCT reaching or exceeding the VdetH voltage
until RESET reverses (the RESET transmission delay time: TdLH) is given by the following equation:
switches from high level to low level. The watchdog timer reset time TWL is given by the following equation:
The watchdog timer monitor time TWH is given by the following equation:
Use a TWCLK input pulse width of at least 500 ns.
discharging to charging and then switches back to discharging once it charges to VthH.
reset detection will operate normally.
discharged.
0
0
0
0
0
0
VthH
Vdet
VdetH
VthL
Vs Detection voltage
TdLH (s) ≈ (1.26 × CT (µF)) / Icto (µA)
TWL(s) ≈ (1.02 × CT (µF)) / Icto (µA)
TWH(s) ≈ (1.02 × CT (µF)) / Ictc (µA)
(1) (2) (3) (4)
1,25V(Typ.)
TdLH
TWL
TWH
(5)
TWCLK
Fig.15
(6)
OUT
R1=1.56MΩ
(7)
TWCLK
R2=3.56MΩ
VHS
(All resistance values are typical ones.)
(4) (5) (8) (9)
When VINH = high
WDT current off
Fig.16
(4)(5)
[2]
[3]
[1]
(10)
(2) (10) (2) (4) (5)
(3)
5/8
For a basic detection voltage of 4.1 V,
To change the detection voltage,
insert pull-down resistor R3 (with a resistance value lower than R1)
between the Vs and GND pins, and pull-up resistor R4 (with a
resistance value lower than R2) between the Vs and Vo pins.
(3)
Vdet = Vs × (R1 + R2 / R1)
Vdet = Vs × (R3 + R4 / R3) [R3<<R1, R4<<R2]
(10)
(11)
VdetH = Vdet + VHS