BD9845FV-E2 Rohm Semiconductor, BD9845FV-E2 Datasheet - Page 10

• Manufacturer Part Number: BD9845FV-E2
• Description: IC REG SW STEP DOWN 1CH 14-SSOP
• Manufacturer: Rohm Semiconductor
• Type: Step-Down (Buck)r

Specifications of BD9845FV-E2

• Internal Switch(s): No
• Synchronous Rectifier: No
• Number Of Outputs: 1
• Current - Output: 1A
• Frequency - Switching: 100kHz ~ 1.5MHz
• Voltage - Input: 3.6 ~ 35 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 14-SSOP
• Power - Output: 500mW
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Voltage - Output: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• Other names: BD9845FV-E2TR

●Timing chart
© 2009 ROHM Co., Ltd. All rights reserved.
BD9845FV
www.rohm.com
1.8Vtyp.
0.9Vtyp.
Vcc-5V
◎Starting characteristics (UVLO cancel) and standby operation
◎Overcurrent detection (When output is shorted: Overcurrent detection and cancel are repeated at a specified time interval.)
VREF
STB
VCC
OUT
C5V
Vcc
SS
1V
DT
FB
CT
When UVLO (Vcc , and VREF) is
canceled, (Vcc - 5V) Reg is started.
Vcc-5V
VREF停止電圧
VREF起動電圧
UVLO(Vcc,VREF)とも解除になると
Vocpth
OCP+
OCP-
OUT
C5V
Vcc
Vcc
CT
DT
FB
SS
(Vcc-5V)Regが起動
(1) UVLO (Vcc) is canceled when Vcc>3.2V.
①Vcc＞3.2VでUVLO(Vcc)解除
UVLO
UVLO保護状態
(2) UVLO (VREF) is canceled when VREF>2.2V.
 UVLO (TSD) Minimum retention time (0.2 ms)
②VREF＞2.2VでUVLO(VREF)解除
Overcurrent detection
☆UVLO(TSD)最小保持時間(0.2msec)
(3) UVLO (C5V) is canceled when C5V<Vcc - 3V.
CT: Pull-up to VREF during UVLO period
CT
 UVLO
③C5V＜Vcc-3VでUVLO(C5V)解除
■UVLOは、
①Vcc②VREF③C5V全てが通常状態となった後、☆最小保持時間後に解除、
①Vcc②VREF③C5VのいずれかでUVLOを検出した場合には、ただちに出力を停止。
OUT
DT
:UVLO期間中はVREFにプルアップ
C5V
過電流検出
FB: Pull-down during UVLO
FB：UVLO期間中はプルダウン
FB
Delay time in detection
検出時の遅延時間
tdocpth
DT: Pull-down during UVLO
DT：UVLO期間中はプルダウン
Set SS by external capacity.
Although SS is notated by the same time axis in the figure for showing the image,
actually set sufficiently longer time in comparison with the cycle of triangular wave.
SSは外付け容量によって設定します。
図中ではイメージをつかんで頂く為同じ時間軸で表記しておりますが、
実際は三角波の周期に比べ十分に長い時間を設定します。
(FB→"L”)
DT→"L”
SS→"L”
10/15
Minimum time retaining detection condition
tdocpre 1.6mS
検出状態を保持する最小時間
Open DT (FB) and SS.
DT(FB)、SSを開放
tdocpre 1.6mS
OCP-
Overcurrent detection
過電流検出
OCP+
OUT
Overcurrent detection
過電流検出
C5V
UVLO voltage [unit: V]
Item
Threshold voltage (VCC)
Hysteresis
Threshold voltage (VREF)
Threshold voltage (C5V)
2009.05 - Rev.A
Technical Note
Min
3.0
2.0
-
-
0.15
Typ
3.2
2.2
3.0
Max
0.25
3.4
2.4
3.4