Introduction to DIO1568 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

Board Resources #

Function Description #

The detailed assignment of the peripheral interfaces on the Development board is as follows:

Dual-view diagram of DIO1568 Analog Switch — **Eicut DIO1568 Analog Switch Pinout & Connectors**

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

Board Interfaces #

Annotated top view of DIO1568 Switch Board — **Pin Header Pinout**

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.

Board Dimensions #

Dimensioned drawing of DIO1568 Analog Switch — **DIO1568 Analog Switch Dimensions : 30 * 40 mm**

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)

Resources Downloads #

FAQ #

What is the DIO1568 EVB?

A ready-to-use development board for the DIO1568 — an ultra-low Ron (0.85 Ω) quad SPDT analog switch designed specifically for dual-SIM / DSDS smartphones and IoT devices.

How do I switch between SIM 1 and SIM 2?

Just control the SEL pin (P3-2):
• Logic HIGH → SIM 2 active
• Logic LOW → SIM 1 active
You can use a jumper or directly drive it from any MCU GPIO.

What voltage can I use to power the board?

Wide range: 1.65 V to 5.5 V on VCC pin (P3-3). Most users connect 1.8 V or 3.0 V directly from the baseband processor or PMIC.

Does it support 2FF (standard) SIM cards?

Yes — two full-size 2FF (mini-SIM) push-push card holders are integrated on the board. Perfect for quick testing without soldering.

How do I connect the board to my phone motherboard?

Two options:
• Use the onboard 6-pin FPC connector (standard 0.5 mm pitch)
• Or solder wires to the P2 header (VSIM, RST, CLK, DATA, VCC, GND)

Is break-before-make switching guaranteed?

Yes — the DIO1568 has built-in break-before-make timing to prevent shorting between the two SIM cards during switching.

How low is the power consumption?

Extremely low — <1 µA quiescent current even when control voltage is lower than VCC. Ideal for always-on dual-SIM phones.

Can I drive the SEL pin directly from a 1.8 V GPIO?

Yes — the control input threshold is independent of VCC. You can safely connect 1.8 V baseband GPIO even if VCC is 3.0 V.

Is the board suitable for final product integration?

Absolutely — use the provided layout and schematic as reference. The chip comes in tiny 1.8×2.6 mm QFN — perfect for space-constrained designs.

Does it affect SIM card signal quality?

No — only 0.85 Ω Ron and 20 pF capacitance on DAT/CLK/RST lines ensure minimal impact on rise/fall times and eye diagram.