The SN74GTL2003 device provides eight NMOS pass transistors (Sn and Dn) with a common gate (G_REF) and a reference transistor (S_REF and D_REF). The low ON-state resistance of the switch allows connections to be made with minimal propagation delay. With no direction control pin required, the device allows bidirectional voltage translations from any voltage (0.95 V to 5 V) to any voltage (0.95 V to 5 V).

When the Sn or Dn port is LOW, the clamp is in the ON state and a low-resistance connection exists between the Sn and Dn ports. Assuming the higher voltage is on the Dn port, when the Dn port is HIGH, the voltage on the Sn port is limited to the voltage set by the reference transistor (S_REF). When the Sn port is HIGH, the Dn port is pulled to VCC by the pullup resistors.