BD9C401EFJ-E2

Part: BD9C401EFJ — ROHM

Type: Synchronous Buck DC/DC Converter

Description: 4.5–18 V input, 4 A single synchronous buck converter with integrated 65 mΩ / 35 mΩ MOSFETs, 0.8 V ±1% reference and 500 kHz switching frequency.

Operating Conditions:

• Supply voltage: 4.5–18.0 V
• Operating temperature: -40 to +85 °C
• Output current: up to 4.0 A
• Output voltage setting range: VIN × 0.125 to VIN × 0.7 (VIN × 0.125 ≥ 0.8 V)

Absolute Maximum Ratings:

• Max supply voltage (VIN): 20 V
• SW pin voltage: 20 V
• EN pin voltage: 20 V
• FB, COMP pin voltage: 7 V
• Max junction temperature: 150 °C
• Storage temperature: -55 to +150 °C
• Power dissipation: 3.76 W (70 × 70 × 1.6 mm 4-layer board)

Key Specs:

• FB voltage: 0.800 V typ (0.792–0.808 V), Ta = 25 °C
• Switching frequency: 500 kHz typ (450–550 kHz)
• High-side FET on-resistance: 65 mΩ typ (VIN = 12 V, ISW = -1 A)
• Low-side FET on-resistance: 35 mΩ typ (VIN = 12 V, ISW = -1 A)
• Circuit current, active: 1.5 mA typ (2.5 mA max)
• Circuit current, standby: 1.0 μA typ (10 μA max), VEN = 0 V
• Current limit: 4.5 A min
• UVLO threshold: 4.0 V typ rising (3.75–4.25 V), 0.2 V hysteresis
• Soft-start time: 1.0 ms typ (0.5–2.0 ms)
• EN thresholds: high ≥ 2.0 V, low ≤ 0.8 V

Features:

• Current mode control with high-speed transient response
• Easily set phase compensation
• Over current protection
• Short circuit protection (off-latch)
• Thermal shutdown (175 °C typ)
• Under voltage lockout
• Fixed soft start

Applications:

• LCD TVs
• Set-top boxes
• DVD/Blu-ray disc players/recorders
• Broadband network and communication interfaces
• Entertainment devices

Package:

• HTSOP-J8 (exposed pad; 7 pins plus E-Pad)

• ■ Synchronous Single DC/DC Converter
• ■ Over Current Protection
• ■ Thermal Shutdown Protection
• ■ Under Voltage Lockout Protection
• ■ Short Circuit Protection
• ■ Fixed Soft Start Function

• ■ LCD TVs
• ■ Set-top Boxes
• ■ DVD/Blu-ray Disc Players/Recorders
• ■ Broadband Network and Communication Interface
• ■ Entertainment Devices

Figure 2. Pin Assignment

(Ta = 25 C, VIN = 12 V, VEN = 5 V unless otherwise specified)

(Note 1) VFB :FB Pin Voltage, VEN :EN Pin Voltage, ISW :SW Pin Current

(Note 2) Current capability should not exceed Pd.

(Note1) Derate by 30.08 mW when operating above 25 C.

Caution: Operating the IC over the absolute maximum ratings may damage the IC. The damage can either be a short circuit between pins or an open circuit between pins and the internal circuitry. Therefore, it is important to consider circuit protection measures, such as adding a fuse, in case the IC is operated over the absolute maximum ratings.

(Note 1) VIN x 0.125 ≥ 0.8 [V]

When the chip temperature exceeds Tj = 175°C (Typ), the DC/DC converter output is stopped. The thermal shutdown circuit is intended for shutting down the IC from thermal runaway in an abnormal state with the temperature exceeding Tjmax = 150 C (Typ). It is not meant to protect or guarantee the soundness of the application. Do not use the function of this circuit for application protection design.

VIN

HG : Hi side FET GATE signal

LG : Low side FET GATE signal

Figure 1. Application Circuit

Product structure: silicon monolithic integrated circuit

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This product has no protection against radioactive rays

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