In the field of power management chips, the core of a compatible replacement solution lies in the high degree of matching in pin definitions, electrical parameters, and functional characteristics. The AWK6943, as a high-performance synchronous buck converter, has become an ideal upgrade replacement solution due to its identical package specifications, compatible electrical parameters, and optimized performance compared to the MP9943. The following analysis is divided into two aspects: compatibility and technical advantages.
I. Compatibility Analysis: Seamless Replacement from Packaging to Functionality
1. Full Compatibility in Packaging and Pins
- Package Specification: Both devices use the ultra-compact QFN-8 (3mm×3mm) package with identical pin layout and pad dimensions, allowing for direct replacement without modifying the PCB design.
- Pin Function Mapping:
Pin Name | MP9943 Function Description | AWK6943 Function Description | Compatibility Instruction |
FB | Feedback voltage input, sets output voltage | Feedback voltage input, sets output voltage | Direct docking, only voltage divider resistors need to be adjusted |
VCC | Internal control circuit power supply | Internal control circuit power supply | Consistent power supply logic, compatible capacitor configuration |
EN/SYNC (MP9943) / EN (AWK6943) | Enable/synchronization input, supports external clock synchronization | Enable input, supports frequency synchronization (200kHz-2.2MHz) | Equivalent functions, EN pin is compatible with synchronization control |
BST | Bootstrap capacitor connection terminal, drives high-side MOSFET | Bootstrap capacitor connection terminal, drives high-side MOSFET | Consistent capacitor configuration parameters, supports 20Ω current limiting resistor |
SW | Switch node output, connects to inductor | Switch node output, connects to inductor | Direct docking, no need to modify PCB traces |
VIN/IN | Input voltage terminal | Input voltage terminal | Consistent electrical definition, supports wide voltage input |
GND | System ground | System ground | Common ground design, PCB layout compatible |
PG | Power good indication (open drain output) | Power good indication (open drain output) | Consistent output logic, pull-up resistor compatible |
2. Highly Matching Electrical Parameters
- Input and Output Range:
- MP9943: Input 4V-36V, output voltage adjustable from 0.8V, peak current 3A;
- AWK6943: Input 3V-36V (compatible with lower start-up voltage), output voltage adjustable from 0V to 24V, peak current 3A, fully covering the application scenarios of MP9943.
- Switching Frequency and Control Mode:
- Both use a fixed 410kHz peak current mode control, supporting external clock synchronization (200kHz-2.2MHz). The inductor and output capacitor parameters can be directly carried over.
- Equivalent Protection Functions:
- Both integrate cycle-by-cycle overcurrent protection (OCP), thermal shutdown (TSD), undervoltage lockout (UVLO), and hiccup mode. The fault handling logic is consistent, ensuring system reliability.
II. Technical Advantages of AWK6943 Compared to MP9943
1. Lower Static Power Consumption, Extended Battery Life
- Static Current (I_Q):
- MP9943: Typical value 0.5mA (V_EN=2V, V_FB=1V);
- AWK6943: Typical value 30μA (V_FB=1.05V), with a 94% reduction in power consumption. This is especially suitable for battery-powered devices (such as drones and handheld tools), significantly extending battery life.
- Light-Load Efficiency Optimization:
- AWK6943 employs an advanced PFM control mode, automatically skipping pulses under light load to reduce switching losses. The efficiency is 8-10% higher than that of MP9943 at a 10mA load.
2. Higher Performance Indicators, Suitable for Complex Scenarios
- Minimum On-Time (T_ON_MIN):
- MP9943: 70ns;
- AWK6943: 40ns (typical value), supporting a higher duty cycle (up to 98.5%). This provides more stable performance and lower voltage drop in scenarios where the input voltage is close to the output voltage (such as automotive cold start).
- Feedback Voltage Accuracy:
- MP9943: Feedback voltage V_FB=0.8V (±1.75%);
- AWK6943: V_FB=1.0V (±1.5%). The higher reference voltage reduces the precision requirement for voltage divider resistors, enhances noise immunity, and improves output voltage stability.
3. Automotive-Grade Certification and Flexible Configuration
- AEC-Q100 Certification:
- AWK6943 has passed automotive-grade reliability certification, making it suitable for automotive systems (such as cockpit electronics and ADAS). MP9943 does not have a clear automotive-grade qualification. Replacing it with AWK6943 can expand the application scenarios.
- Adjustable UVLO Threshold:
- MP9943: Fixed UVLO threshold (rising 3.5V, falling 3.3V);
- AWK6943: The UVLO threshold can be flexibly adjusted through a voltage divider on the EN pin, adapting to different power system undervoltage protection requirements. For example, in industrial equipment, a higher start-up threshold can be set.
4. Thermal and EMI Optimization
- Thermal Shutdown Characteristics:
- AWK6943 has a thermal shutdown threshold of 165°C (with a 15°C hysteresis), which triggers protection earlier than MP9943 (170°C). Combined with lower on-resistance (R_DSON_H=105mΩ, R_DSON_L=65mΩ), it generates less heat, making it suitable for high-density layouts.
- EMI Suppression:
- With built-in compensation circuits and optimized switch node design, AWK6943 reduces EMI radiation by about 5dB compared to MP9943, reducing the need for external filtering components and further shrinking the solution size.
III. Design Considerations for Replacement
1. Output Voltage Adjustment:
- Since the V_FB of AWK6943 is 1.0V, the voltage divider resistor needs to be recalculated when replacing:
\[
R_{FBB} = \frac{V_{REF} \times R_{FBT}}{V_{OUT} - V_{REF}} \quad (V_{REF}=1.0V)
\]
- For example, when MP9943 outputs 3.3V with R7=41.2kΩ and R8=13kΩ, after replacing with AWK6943, if R_FBT=100kΩ, then R_FBB=43kΩ.
2. Inductor and Capacitor Continuation:
- The inductor value can be directly carried over (e.g., 10μH). It is recommended to use low-ESR ceramic capacitors for the output capacitor to ensure that the ripple voltage meets the requirements:
\[
\Delta V_{OUT} = \frac{V_{OUT} \times (1-D)}{8 \times f_{SW}^2 \times L \times C_{OUT}}
\]
3. EN Pin Configuration:
- If synchronization functionality needs to be retained, the EN pin of AWK6943 can be connected to an external clock (200kHz-2.2MHz) with a pulse width of less than 2μs, consistent with the logic of MP9943's EN/SYNC pin.
The replacement of MP9943 with AWK6943 is not only a simple compatibility in pins and functions but also a comprehensive upgrade in performance and reliability. With lower power consumption, higher efficiency, automotive-grade certification, and flexible configuration features, AWK6943 has a greater advantage in consumer electronics, industrial control, automotive systems, and other scenarios. For designs that need to optimize battery life, enhance stability, or expand application scenarios, AWK6943 is an ideal choice that combines cost-effectiveness and technical advantages.
About Mandu Technology
Shenzhen Mandu Technology Co., Ltd. has steadfastly centered its operations on the distribution of high-performance, high-quality, and highly reliable integrated circuit products. Its portfolio encompasses memory chips, differential crystal oscillators, and MCU microcontrollers, while progressively integrating analog signal chain products. The company prides itself on delivering comprehensive and cost-effective solutions to its customers. Its products find applications across a broad spectrum of industries, including but not limited to network communication, industrial control, robotics, medical equipment, personal health, and numerous other fields.
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