ST1G3234 and ST4G323x series
1-bit and 4-bit level transistors

ST1G3234 Product Page ST4G323x Product Selector The ST1G3234 is a dual supply low voltage CMOS 1-bit uni-directional Level Translator, while the ST4G3234 (4 up or 4 down) and ST4G3235 (2 up and 2 down) are dual supply low voltage CMOS 4-bit uni-directional Level Translators.

With the need to differentiate products from competitors, mobile phone makers are putting on the market products with unique and differentiating factors from their competitors. Different voltage supply for different components is incorporated during the design stage of a new product. Level translators are used to up/down translate signal of components with different voltage supplies; for example an ASIC with 2.8V/3.3V and the baseband processor with 1.8V voltage supply. The ST1G3234, ST4G3235 and ST4G3234 have been designed for use as an interface between a 3.3V bus and a 2.5V or 1.8V bus in a mixed 3.3V/1.8V, 3.3V/2.5V, 1.8V/1.4V and 2.5V/1.8V supply systems. These devices achieve high speed operation while maintaining the CMOS low power dissipation.

High speed: tPD = 4.4ns (MAX.) at TA = 85°C VCCB = 1.65V; VCCA = 3.0V
Low power dissipation: ICCA = ICCB = 5µA (MAX.) at TA = 85°C
Balanced propagation delays: tPLH = tPHL
Power down protection on inputs and outputs
26Ω series resistor on A side outputs
Operating voltage range:
   VCCA(OPR) = 1.4V to 3.6V (1.2V data retention)
   VCCB(OPR) = 1.4V to 3.6V (1.2V data retention)
Latch-up performance exceeds 500mA (JESD 17)
RoHS compliant for Flip-Chip package

The ST1G3234, ST4G3234 and ST4G3235 are dual supply low voltage CMOS fabricated with sub-micron silicon gate. Designed for use as an interface between a 3.3V bus and a 2.5V or 1.8V bus in a mixed 3.3V/1.8V, 3.3V/2.5V, 1.8V/1.4V and 2.5V/1.8V supply systems, it achieves high speed operation while maintaining low power dissipation. These devices are intended for one-way asynchronous (uni-directional) communication between data buses. The input and output power down protection disable the device when both power supplies are down, so that the buses are effectively isolated. The input tolerant buffers allow translating VCCB compatible signals and greater signals than VCCB up/down to VCCA. The 26Ω series resistor on A side outputs are designed to match the trace impedance and thus reduce overshoot and undershoot during operation. All inputs are equipped with protection circuits against static discharge, giving them ESD immunity and transient excess voltage.

The device packaging is especially designed with minimum dimensions to suit the space-constraints of mobile phones. The ST1G3234 is available in 1.36mm x 1.02mm, lead-free Flip-Chip, while the ST4G323x series are available in 2.04mm x 1.44mm lead-free, Flip-Chip package. Both packages have a pitch of 500µm.

Application of level translators in mobile phones

Different technology and speed of development of off-the-shelf components resulted in different power supply requirements. Level translators are created for bridging these components.

P / N	Package	Dimensions
ST1G3234BJR	Flip-Chip 5	1.36mm x 1.02mm
ST4G3234BJR	Flip-Chip11	2.04mm x 1.44mm
ST4G3235BJR	Flip-Chip11