Introduction to DIO1568 Dual Sim Card Analog Switch
Basic Overview #
The DIO1568 Evaluation Board (EVB) provides an easy and efficient way to test and develop prototypes using the DIO1568, a low-power quad SPDT analog switch specifically designed for dual-SIM card switching applications. Operating from a wide supply voltage range of 1.65 V to 5.5 V, this device features extremely low on-resistance of just 0.85 Ω across the SIM signal paths and ensures reliable break-before-make switching performance thanks to advanced sub-micron CMOS technology. It also draws minimal quiescent current even when the control logic voltage is lower than VCC, allowing direct connection to baseband processor GPIO pins in smartphones and other portable devices. The DIO1568 is offered in two small-footprint QFN packages: 1.8 × 2.6 mm (16-pin) and 3 × 3 mm (16-pin).
Feature List #
- Switch type: Quad SPDT (4×)
- Supply voltage: 1.65 V to 5.5 V
- Low on-resistance: 0.85 Ω (SIM path); 2.7 Ω (other paths)
- Capacitance: 20 pF CON at DAT/CLK/RST path
- Low quiescent power consumption (suitable for battery-powered devices)
- Package options: 16‑lead QFN 1.8×2.6 mm and 16‑lead QFN 3×3 mm
Development Board Configuration #
The detailed assignment of the peripheral interfaces on the Development board is as follows:
| NO. | Name | Silkscreen | Comment |
|---|---|---|---|
| 1 | 4pin header | P3 | header 2.54mm |
| 2 | 6pin header | P2 | header 2.54mm |
| 3 | Dual Sim card case | – | 2FF SIM Card |
| 4 | FPC Connector | P1 | FPC 6pin |
Function Description #
Pin Description #
| NO. | Name | Silkscreen | Comment |
|---|---|---|---|
| P3-1 | Ground | GND | – |
| P3-2 | Select | Sel | 0 – Power |
| P3-3 | Power | VCC | 1.65~4.3V |
| P3-4 | Ground | GND | – |
| P2-1 | VSIM | VSIM | These pins are similar to the pins of the FPC connector. You can use them if you do not use the FPC connector. |
| P2-2 | VCC | VCC | |
| P2-3 | RST | RST | |
| P2-4 | CLK | CLK | |
| P2-5 | DATA | DATA | |
| P2-6 | Simcard-GND | SIMG |
For switching between two SIM cards, you can connect the Select pin (pin header P3) to ground or VCC manually with a jumper, or you can control this pin using a microcontroller to set it high or low.
DIO1568 Dual Sim Card Analog Switch Dimensions #
How the EVB Helps — Faster, Easier Design #
- Rapid evaluation of electrical performance (on-resistance, switching, leakage) without PCB redesign.
- Reference layout and footprint for the QFN packages remove guesswork and speed board bring-up.
- Breakout connections for SIM DAT/CLK/RST and control pins allow quick functional tests and firmware integration.
- Pre-routed decoupling and recommended component placements reduce signal issues and shorten debug time.
- Demonstrates low-power behavior and direct GPIO interfacing to confirm compatibility with target baseband processors.
Use the DIO1568 EVB to accelerate prototyping, validate performance in your target system, and shorten the path from concept to final design.
Getting Started Preparation #
- Step 1: Connect the board power
- Step 2: Place the SIM cards in the SIM card case
- Step 3: Switch between SIM cards by High and Low the select pin
- Step 4: Connect the board to your microcontroller with the FPC connector or the header pin(P2)