SIM3U146-B-GM Silicon Labs, SIM3U146-B-GM Datasheet - Page 82

• Manufacturer Part Number: SIM3U146-B-GM
• Description: ARM Microcontrollers - MCU ARM Cortex-M3 USB 64KB QFN64
• Manufacturer: Silicon Labs

Specifications of SIM3U146-B-GM

• Rohs: yes
• Core: ARM Cortex M3
• Processor Series: SIM3U1xx
• Data Bus Width: 32 bit
• Maximum Clock Frequency: 80 MHz
• Program Memory Size: 64 KB
• Data Ram Size: 32 KB
• On-chip Adc: Yes
• Operating Supply Voltage: 1.8 V to 3.6 V
• Operating Temperature Range: - 40 C to + 85 C
• Package / Case: QFN-64
• Mounting Style: SMD/SMT
• Interface Type: 2 x I2C, I2S, 3 x SPI, 2 x USART, 2 x UART
• Number Of Programmable I/os: 65
• Number Of Timers: 2 x 32 bit
• Supply Voltage - Max: 3.6 V

SiM3U1xx
6.6.1. QFN-64 Solder Mask Design
All metal pads are to be non-solder mask defined (NSMD). Clearance between the solder mask and the metal pad
is to be 60 µm minimum, all the way around the pad.
6.6.2. QFN-64 Stencil Design
6.6.3. QFN-64 Card Assembly
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1. A stainless steel, laser-cut and electro-polished stencil with trapezoidal walls should be used to assure
2. The stencil thickness should be 0.125 mm (5 mils).
3. The ratio of stencil aperture to land pad size should be 1:1 for all pads.
4. A 3x3 array of 1.0 mm square openings on a 1.5 mm pitch should be used for the center ground pad.
1. A No-Clean, Type-3 solder paste is recommended.
2. The recommended card reflow profile is per the JEDEC/IPC J-STD-020 specification for Small Body
good solder paste release.
Components.
Rev. 1.0