I don't know if the small partners have any impression, in the second half of last year, ZMI Zimi launched a 33W 1A1C fast charger HA728, designed for the apple iPhone 13 new machine design, the new green color is full of small and fresh, so it has been loved and sought after by many people.
Not long ago, the charging head network learned that Zimi has launched a new product specifically for fruit powder - ZMI GaN3 charger 35W (2C), compared with the previous one, the interface configuration has become a dual C port, and the maximum power has also been mentioned to 35W. The new charger is not only based on Gallium Nitride Black Technology, but also uses a new dynamic power distribution technology to better charge two Apple devices.
At present, the charger has been sold in the Zimi Jingdong self-operated flagship store, priced at 89 yuan, and there are two styles of white and green. Charging head network is also the first time to purchase back for evaluation and disassembly, let's take a look at the material workmanship of the new product.
First, the appearance of Zimi 35W GaN3 charger
The new charger has two colors of white and green, and the charging head network is purchased back, one for disassembly and one for evaluation, so that everyone can understand.
The ZMI brand logo and 35W MAX are printed on the top of the front of the box, the charger appearance map in the middle, and the product name and GaN logo are printed on the bottom.
Product parameter information is printed on the back.
The package contains a charger and instruction manual.
This time the dismantling is a green model, the overall look is a little fresh, the shell frosted corners are too rounded.
The front of the fuselage is intaglio with 35W power lettering.
Charger parameters are printed on the input housing, and the biplane design is added on both sides to improve stability when using.
Close-up of charger parameters
Model: HA726
Input: 100-240V~50/60HZ 1.2A
Output parameters:
单口输出：5V3A、9V3A、11V3A、12V2.9A、15V2.33A、20V1.75A，35W MAX
Dual output: the maximum output power is 35W, this product adopts dynamic power distribution technology
Manufacturer: Nanjing Kuke Electronic Technology Co., Ltd
Producer: Jiangsu Zimi Electronic Technology Co., Ltd
The charger has passed 3C certification.
The charger is equipped with folding national standard plugs for easy carrying and storage.
The output is equipped with dual USB-C interface, the single port supports the maximum output of 35W, and the maximum total power of the dual port is also 35W, and the dynamic power distribution technology is used to achieve intelligent power distribution.
The measured height of the charger body is 46mm.
The width is 47.87mm.
The thickness is 27.86mm.
Compared with Apple's 30W charger, power, volume, and number of interfaces have advantages.
The size of the charger held in the hand is intuitive.
The net weight of the charger is about 78g.
Use the Chargelab POWER-Z KT002 to test the C port to support QC2.0/3.0 and PD3.0 universal fast charging protocols.
In addition, the PDO message shows that the C port also has five fixed voltage levels of 5V3A, 9V3A, 12V2.9A, 15V2.33A, and 20V1.75A.
Another C-port compatible protocol was measured to be exactly the same.
PDO message is also the same, the two C ports support power blind plug, easy to use daily.
Second, zimi 35W GaN3 charger disassembly
Take apart the output housing and remove the PCBA module, and the housing is ultrasonically soldered in a package.
The housing is made of PC fireproof material, the feet are fixed with black plastic plates and screws, and the PCB board is energized by touching the PCB board through metal shrapnel.
The back of the PCB board is covered with mylar tablets and brass heat sinks, and the heat sinks are soldered and fixed.
The measured module length is 42.83mm.
The width is 43.96mm.
The thickness is 23mm.
The gap between the components on the front of the board is heavily filled with white glue reinforcement, and there is an insulated isolation plate between the primary stages.
At a glance on the back of the board, the primary core chip is also covered with white glue to dissipate heat.
At a glance at the front of the PCB board, the area between the two output boards is equipped with a protocol chip.
On the back of the board, there is a rectifier bridge, a gallium nitride sealing chip of the south core, a secondary synchronous rectifier chip and a step-by-step conversion chip.
Through observation, it is found that this charger adopts a high-frequency QR switching power supply architecture with very high utilization rate, fixed voltage output, built-in two DC-DC boost voltages, and uses a protocol chip to control the dual-port output to achieve intelligent power distribution. Let's start with the inputs to understand each device.
At a glance at the inputs, from the right fuse to the left transformer, the primary devices are laid out sequentially.
After the charger is energized, the current first passes through the delay fuse, and when the current exceeds the fuse limit, the circuit is fused off, and the fuse specification is 2A 250V.
Then through the common mode inductor, the two wires are wound together to filter out EMI interference.
It then passes through the safety X capacitor to suppress differential mode interference.
Then through the NTC thermistor, NTC thermistor is used to suppress the inrush current when plugged in, reduce the spark of plugging, the temperature rises during normal operation, the resistance is reduced, and the loss is reduced.
After EMI circuit filtering, the YANGJE ABS210 rectifier bridge converts ac power into pulsating direct current.
The pulsating DC is output to DC through high-voltage filtered electrolytic capacitors and I-form differential mode inductance filtering. Two high voltage filter electrolytic capacitors from AiSHi Aihua are both 400V 27μF.
I-beam differential mode inductive jacket insulated tube.
The main control chip power supply capacitor is also from Aihua, with a specification of 100V 4.7μF.
The switching power supply main control chip adopts NANXIN Semiconductor's SC3056, which is a gallium nitride sealing chip with built-in gallium nitride power devices and controllers. High-frequency quasi-resonant flyback control with high efficiency and reliability over the full load range, derived from Southern Semiconductor's SC305x GaN Combo series. The SC3056 integrates a 650V pressure-resistant gallium nitride switch tube, which can easily drive the output power range of 30W to 40W.
The SC3056 operates in QR and DCM modes with valley turn-on for efficiency, adaptive frequency foldback for high efficiency over the full load range, and Burst Mode operation at no load to reduce standby power consumption. The converter has built-in high-voltage start-up circuitry for ultra-low standby power consumption and ultra-fast start-up speed.
The SC3056 integrates internal soft-start circuitry and segmented power supply circuitry for an ultra-wide output range. Ultra-low operating current in burst and fault modes to meet standby efficiency requirements. The maximum operating frequency is 175KHz, which greatly reduces the size and cost of magnetic devices. Full power range with jitter feature to improve EMI performance.
The chip has built-in overtemperature protection, power supply overvoltage protection, power supply undervoltage lockout, cycle-by-cycle current limiting, two-stage overcurrent protection, output overvoltage protection, output short circuit protection and overload protection, providing a complete and comprehensive protection function.
According to the charging head network, Nanxin Semiconductor's fast charging solution is widely used in chargers, wireless charging, car charging, charging treasure, energy storage power supply and other aspects, and has been Luxun Precision 65W 1A1C gallium nitride fast charging, Huawei 66W super fast charging car charging, Huawei 50W super fast charging wireless car charging, Zimi 2000W PD fast charging mobile power supply, Xiaomi 20000mAh mobile power supply 50W super flash charging version, Samsung 10000mAh 25W PD fast charging mobile power supply, Bull 600W outdoor mobile power supply, Anker PowerHouse II 400 outdoor power supply and dozens of other products are used, and the quality is highly recognized by customers.
The direct current enters the primary side of the transformer, and the main control chip switches on and off at high frequency, and finally converts it into a low-voltage AC output through the transformer.
At a glance at the output terminal, the two USB-C female seats are welded vertically on the small board, and the left side of the board is equipped with a buck-boost inductor and an output filter capacitor, and a solid capacitor is provided in the lower right corner of the motherboard for switching power supply output filtering and synchronous buck-boost input filtering.
Y capacitor close-up for suppressing common-mode interference.
CT 1018 optocoupler, an optoelectronic isolation device that changes the luminous intensity of the internal LIGHT-emitting diode through changes in the current at the input, adjusts the degree of conduction of the built-in phototransistor at the output for output voltage feedback.
The transformer AC buck output is converted to pulsating DC by synchronous rectifier chip rectification. The synchronous rectifier chip adopts the South Core SC3511, which is an intelligent and fast shutdown synchronous rectifier with an integrated 100V 10mΩ synchronous rectifier tube, which can replace the Schottky diode for higher system conversion efficiency.
The SC3511 eliminates the need for auxiliary coil power, has a built-in proprietary on-check circuit, and has very low quiescent current, reducing overall standby power consumption. Support DCM, CCM and QR operating modes, support high-end and low-end synchronous rectification applications, using SOP8 package, suitable for AC-DC adapter, USB PD fast charging, flyback switching power supply, etc.
Pulsating DC is filtered into DC by a solid capacitor from Emerald with a specification of 25V 470μF.
Then through the secondary buck-boost circuit to adjust the output voltage, both interfaces are using the South Core SC8721 built-in switch transistor synchronous buck-boost converter, which has an integrated four-tube H-bridge buck-boost switch, the input and output voltage range is 2.7-22V. Support dynamic output voltage adjustment, switching frequency adjustable, support output line compensation, output current monitoring, support I2C bus control output voltage regulation and output current limit regulation, built-in comprehensive protection function.
Nanxin SC8721 data information.
The charging head network learned that the products using the South Core SC8721 also include ANKER 25600mAh power bank, Nubia Red Devil 45W USB PD deuterium power bank, Xiaomi 20000mAh power bank, thinkplus 14000mAh 45W PD fast charge mobile power bank and so on.
Another synchronous rectifier step-up and drop-down conversion chip is also the South Core SC8721.
Close-up of two magnetic ring inductors.
USB-C interface output filtering solid capacitors are also from Emerald, and the specifications are 25V 220μF.
Dual C-port protocol chip, Weiyi WT6639F, is a dual-port USB PD controller, support USB PD3.0 and PPS fast charging. WT6639F internal integrated USB PD physical layer, voltage detection and current detection amplification, support the use of NMOS tube for VBUS switch tube, built-in MTP memory can be configured multiple times.
Both C-port masters have output VBUS switch tubes on the small board, and there are no components on the other side.
The output VBUS switch tube adopts AOS AON7534, NMOS, withstand voltage 30V, and the right side is a TVS diode for ESD protection.
A close-up of the USB-C female seat, with the word KRCONN on the metal case, indicates that the female seat is provided by Jingrui Technology.
All disassembled, let's take a family portrait.
Charging head net disassembly summary
Zimi 35W GaN3 charger style and previously disassembled 33W charger is the same, but the interface becomes a dual C port, both support QC, PD universal fast charging protocol, and the maximum output power is 35W, support power blind plug easy to use. In addition, it also supports dynamic power distribution, which is better adapted to dual devices such as MacBook and AirPods Pro, iPhone 13 and iPhone 13 mini to charge at the same time, which is very friendly to fruit powder.
The charging head network found through disassembly that the charger is based on the QR switching power supply and two DC-DC secondary buck-boost circuit architecture design, using the Nanxin Semiconductor SC3056+SC3511 high-integration high-frequency QR switching power supply scheme, and the two DC-DC circuit buck-boost conversion chips are also using nanxin's SC8721, which shows that Zimi recognizes the performance and quality of the Nanxin chip.
The internal use of Weiyi WT6639F dual-port USB PD controller controls the dual C-port output to achieve intelligent power distribution. The use of Aihua electrolytic capacitors and emerald solid capacitors for input and output filtering, the devices used are domestic first-line brands, in addition to a large number of internal glue reinforcement, primary insulation isolation, solid material workmanship.