DCP3601

Part: DCP3601 (DCP3601CDMR) — STMicroelectronics

Type: Synchronous Step-Down (Buck) Converter

Description: 3.3–36 V input, 1 A synchronous buck converter with 1 MHz fixed switching frequency, 110 μA quiescent current (LCM version) and peak current mode control in a SOT23-6L package.

Operating Conditions:

• Supply voltage: 3.3–36 V
• Operating junction temperature: -40 to 150 °C
• Output current: 0 to 1 A
• Switching frequency: 1 MHz typical (0.8–1.2 MHz)

Absolute Maximum Ratings:

• Max supply voltage (VIN): 38 V
• EN pin voltage: -0.3 V to VIN + 0.3 V
• FB pin voltage: -0.3 to 1.5 V
• BOOT-SW differential voltage: -0.3 to 5.5 V
• Max junction temperature: 150 °C
• Storage temperature: -55 to 150 °C

Key Specs:

• Feedback voltage: 0.833 / 0.850 / 0.867 V (min/typ/max, TJ = 25 °C)
• Quiescent current: 110 μA typ, 140 μA max (LCM version, no switching); 1.4 mA typ (LNM version)
• Shutdown current: 4 μA typ, 7 μA max (VEN = 0 V)
• High-side / low-side RDS(on): 0.50 Ω typ (0.60 Ω max) / 0.26 Ω typ (0.40 Ω max), ISW = 0.1 A
• High-side current limit: 1.4 / 1.55 / 1.65 A (VIN = 24 V)
• Low-side current limit: 1.35 / 1.6 / 1.75 A (VIN = 24 V)
• UVLO: 2.85–3.2 V rising, 2.55–2.9 V falling
• Enable threshold: 1.1–1.36 V rising, 0.95–1.22 V falling
• Soft-start time: 1.4 ms typ
• Thermal shutdown: 175 °C typ, recovery 155 °C
• Thermal resistance junction-ambient (SOT23-6L): 160 °C/W
• ESD: HBM ±1000 V, CDM ±500 V

Features:

• 88% typical efficiency at 600 mA (VIN = 24 V, VOUT = 5 V); 91% at VIN = 12 V
• Synchronous rectification with internal compensation
• Peak current mode control
• Two versions: LCM (high efficiency at light load) and LNM (forced PWM, low noise)
• Switching frequency dithering (±5%) for EMI improvement
• Output overvoltage protection, overcurrent protection (peak and valley), thermal shutdown
• Precision enable

Applications:

• Major appliances
• Smart metering
• Industrial 24 V bus conversion

Package:

• SOT23-6L (6 pins)

• 88% typical efficiency at 600 mA load (V IN = 24 V, V OUT = 5 V)
• 91% typical efficiency at 600 mA load (V IN = 12 V, V OUT = 5 V)
• 3.3 V to 36 V input operating voltage range
• Up to 1 A output current capability
• 110 μA input quiescent current
• 1 MHz fixed switching frequency
• Synchronous rectification
• Internal compensation network
• Peak current mode control
• Two different versions: LCM for high efficiency at light loads and LNM for noise-sensitive applications
• Output overvoltage protection
• Thermal shutdown
• Precision enable
• Switching frequency dithering
• Available in SOT23-6L package

• Major appliances
• Smart metering
• Industrial 24 V bus conversion

TJ = 25 °C, V IN = 24 V unless otherwise specified.

Table 7. Electrical characteristics

Table 7. Electrical characteristics

Table 3. Absolute maximum ratings

Note: Absolute maximum ratings are those values beyond which damage to the device may occur. Functional operation under these conditions is not implied.

Table 4. Thermal data

Note: These values were calculated in accordance with JESD specification and simulated on a 4-layer JEDEC board.

Table 5. Recommended operating conditions

Table 6. ESD ratings

Table 6. ESD ratings

The shutdown block disables the switching activity if the junction temperature is higher than a fixed internal threshold (T SH , refer to Table 7). The thermal sensing element is close to the power elements, ensuring fast and accurate temperature detection. A hysteresis of approximately 20 °C prevents the device from turning ON and OFF too fast. After a thermal protection event has expired, the DCP3601 restarts with a new soft-start.

Table 1. Typical external components

• VOUT L CIN (1) COUT (1) CBOOT (1) R1 R2
• 15 μH 2.2 μF / 50 V 22 μF / 25 V 100 μF / 50 V 73.2 kΩ 15 kΩ
• 5.0 V XGL5050-153 - Coilcraft 744393305150 - Wurth C2012X7R1H225K125AC - TDK C2012X5R1E226M125A - TDK C1608X7R1H104K080AA - TDK - -
• 10 μH 2.2 μF / 50 V 22 μF / 25 V 100 nF / 50 V 86.6 kΩ 30 kΩ
• 3.3 V XGL5050-103 - Coilcraft C2012X7R1H225K125AC - TDK C2012X5R1E226M125A - TDK C1608X7R1H104K080AA - TDK - -

Table 1. Typical external components

To meet environmental requirements, ST offers these devices in different grades of ECOPACK packages, depending on their level of environmental compliance. ECOPACK specifications, grade definitions, and product status are available at: www.st.com. ECOPACK is an ST trademark.