Tsum1pfr-lf Datasheet Online

One of the most critical details in this datasheet is the suffix "-lf". In the electronics industry, this almost universally stands for Lead-Free.

Here is why this matters for your project:

Given the low-frequency operation, pay attention to: Tsum1pfr-lf Datasheet

Example thermal calculation:
If power dissipation = 0.5W (VCC*ICC + gate drive losses), ΔT = 0.5W * 65°C/W = 32.5°C rise. At 85°C ambient, Tj = 117.5°C (safe within 150°C limit).

| Parameter | Condition | Min | Typ | Max | Unit | | :--- | :--- | :--- | :--- | :--- | :--- | | Supply Current (startup) | Before switching | - | 50 | 100 | µA | | Supply Current (operating) | fsw=65kHz, no load | 1.5 | 2.5 | 3.5 | mA | | UVLO Turn-On Threshold | VCC rising | 10.5 | 11.2 | 11.8 | V | | UVLO Hysteresis | - | - | 1.5 | - | V | | Reference Voltage (FB) | TA=25°C | 2.475 | 2.500 | 2.525 | V | | Oscillator Frequency | RT=100kΩ to GND | 50 | 65 | 80 | kHz | | Maximum Duty Cycle | - | 85 | 92 | 95 | % | | CS Trip Voltage | Overcurrent limit | 0.48 | 0.50 | 0.52 | V | | Output Rise Time | CLOAD=1nF | - | 40 | 80 | ns |

Low-frequency note: The -lf suffix ensures the internal oscillator is trimmed for minimal EMI below 80 kHz, suitable for lighting ballasts and legacy power supplies. One of the most critical details in this

A: Check startup resistor from rectified DC to VCC. Typical value is 150kΩ to 300kΩ, 1W. Also verify VCC capacitor (10µF to 47µF) is not leaky.

Title:
Evaluation of the TSUM1PFR-LF — Ultra-Low-Power Mixed-Signal Front-End for IoT Sensor Hubs