产品特点 Features
- LM3478Q in VSSOP-8 package is AEC-Q100 • Distributed Power Systems qualified and manufactured on an Automotive
- Battery Chargers
- Grade Flow
- Offline Power Supplies
- 8-lead VSSOP-8 and SOIC-8 packages
- Telecom Power Supplies
- Internal push-pull driver with 1A peak current
- Automotive Power Systems capability
- Current limit and thermal shutdown KEY SPECIFICATIONS
- Frequency compensation optimized with a
- Wide supply voltage range of 2.97V to 40V capacitor and a resistor
- 100kHz to 1MHz Adjustable clock frequency
- Internal soft start
- ±2.5% (over temperature) internal reference
- Current Mode Operation
- 10µA shutdown current (over temperature)
绝对最大额定值 Absolute Maximum Ratings（TA = 25°C）
超过下表数值可能造成器件永久损坏，设计时请留余量。
| Figure | 2. | 8-Lead | VSSOP-8 | 封装 | Figure2 | 3. | 8-Lead2 | SOIC-8 | 封装2 |
|---|---|---|---|---|---|---|---|---|---|
| Input Voltage | 45V | ||||||||
| FB Pin Voltage | -0.4V < V < 7V | ||||||||
| FA/SD Pin Voltage | -0.4V < V < 7V | ||||||||
| Peak Driver Output | Current | (<10µs) | 1.0A | ||||||
| Storage Temperature | Range | −65°C to +150°C | |||||||
| Junction Temperature | +150°C |
数据来源：原厂规格书
电气特性 Electrical Characteristics（TA = 25°C）
| 符号 | 参数 | 条件 | Typical | Limit | 单位 |
|---|---|---|---|---|---|
| Range. Unless | otherwise specified, V = 12V, | R = 40kΩ | |||
| V | Feedback Voltage V | = 1.4V, | 1.26 | V | |
| ΔV | Feedback Voltage Line | 2.97 ≤ V ≤ 40V | 0.001 | %/V | |
| ΔV Output | Voltage Load I | Source/Sink | ±0.5 | %/A (max) | |
| V Input | Undervoltage Lock-out | 2.85 | V | ||
| V Input | Undervoltage Lock-out | 170 | mV | ||
| Hysteresis | 130 210 | mV (min) mV (max) | |||
| F | Nominal Switching Frequency R | = 40KΩ | 400 | 350 440 | kHz kHz(min) kHz(max) |
| R Driver | Switch On Resistance I | = 0.2A, V = 5V | 16 | Ω | |
| DS1 (ON) | DR IN | ||||
| R Driver DS2 (ON) | Switch On Resistance I | = 0.2A DR | 4.5 | Ω | |
| V | Maximum Drive Voltage V | < 7.2V | V | V | |
| DR (max) | IN | IN | |||
| V | ≥ 7.2V | 7.2 | |||
| D | Maximum Duty Cycle(2) | 100 | % | ||
| T (on) | Minimum On Time | 325 | 210 600 | nsec nsec(min) nsec(max) | |
| I | Supply Current (non-switching) | (3) | 2.7 | mA | |
| I | Quiescent Current in V | = 5V (4), | 5 | µA | |
| Shutdown Mode V | = 5V | 10 | µA (max) | ||
| V | Current Sense Threshold V | = 5V | 156 | mV | |
| Voltage | 135/ 125 | mV (min) | |||
| 180/ 190 | mV (max) | ||||
| V | Short-Circuit Current Limit V | = 5V | 343 | 250 | mV |
| Sense | Voltage | 415 | mV (min) | ||
| V | Internal Compensation Ramp V | = 5V | 92 | mV | |
| Voltage | 52 132 | mV(min) mV(max) | |||
| V ratio V | /V | 0.49 | 0.30 | (min) | |
| V Output | Over-voltage Protection V | = 1.4V | 50 | mV | |
| (with | respect to feedback | 32/ 25 | mV(min) | ||
| VSSOP Package | 78/ 85 | mV(max) | |||
| SOIC Package | 78/100 | mV(max) | |||
| V Output | Over-Voltage V | = 1.4V | 60 | mV | |
| Protection Hysteresis(5) | 20 110 | mV(min) mV(max) | |||
| Product Folder Links: LM3478 | LM3478-Q1 | ||||
| Range. Unless | otherwise specified, V = 12V, | R = 40kΩ | |||
| Gm Error | Amplifier V | = 1.4V | 800 | µmho | |
| Transconductance I | = 100µA (Source/Sink) | 600/ 365 | µmho (min) | ||
| 1000/ 1265 | µmho (max) | ||||
| A Error | Amplifier Voltage Gain V | = 1.4V | 38 | V/V | |
| I | = 100µA (Source/Sink) | 26 44 | V/V (min) V/V (max) | ||
| I Error | Amplifier Output Current | Source, V = 1.4V, V = 0V | 110 | µA | |
| (Source/ Sink) | 80/ 50 | µA (min) | |||
| 140/ 180 | µA (max) | ||||
| Sink, V = 1.4V, V = 1.4V | −140 | µA | |||
| −100/ −85 | µA (min) | ||||
| −180/ −185 | µA (max) | ||||
| V Error | Amplifier Output Voltage | Upper Limit | 2.2 | V | |
| Swing | V | = 0V | 1.8 | V(min) | |
| COMP Pin = Floating | 2.4 | V(max) | |||
| Lower Limit | 0.56 | V | |||
| V | = 1.4V | 0.2 | V(min) | ||
| T | Internal Soft-Start Delay V | = 1.2V, V = Floating | 4 | msec | |
| T Drive | Pin Rise Time | Cgs = 3000pf, V = 0 to 3V | 25 | ns | |
| T Drive | Pin Fall Time | Cgs = 3000pf, V = 0 to 3V | 25 | ns | |
| V | Shutdown threshold (6) | Output = High | 1.27 | 1.4 | V |
| Output = Low | 0.65 | 0.3 | V | ||
| I | Shutdown Pin Current V | = 5V | −1 | µA | |
| V | = 0V | +1 | |||
| I | Feedback Pin Current | 15 | nA | ||
| T | Thermal Shutdown | 165 | °C | ||
| T | Thermal Shutdown Hysteresis | 10 | °C | ||
| θ | Thermal Resistance | VSSOP Package | 200 | °C/W | |
| SOIC Package | 151 | ||||
| Product Folder Links: LM3478 | LM3478-Q1 |
应用领域 Applications
产品应用与封装尺寸
图纸取自该型号原厂规格书的应用电路与封装尺寸章节，点击图片可放大查看原始尺寸标注。