Dual bit line precharge architecture and method for low power dynamic random access memory (DRAM) integrated circuit devices and devices incorporating embedded DRAM
View Patent ↗A dual bit line precharge architecture and method for low power DRAM which provides the low operating voltage of a non-half supply voltage (VCC/2) precharge with the low memory array current consumption and low memory array noise spike of VCC/2 precharge techniques. The architecture and technique of the present invention provides both reference voltage (VSS) precharged sub arrays and VCC precharged sub arrays on the same DRAM memory either with or without the novel charge sharing or charge recycling circuitry between these two different sub arrays as disclosed herein.
1. An integrated circuit device incorporating a random access memory array comprising:
a first pair of cross-coupled transistors coupling a first pair of complementary bit lines to a first node;
a second pair of cross-coupled transistors coupling a second pair of complementary bit lines to a second node;
a first pair of common gate coupled transistors, each coupling one of said first pair of complementary bit lines to a reference voltage level and receiving a precharge signal at said common coupled gates thereof;
a second pair of common gate coupled transistors, each coupling one of said second pair of complementary bit lines to a supply voltage level and receiving a complement of said precharge signal at said common coupled gates thereof; and
first and second additional transistors for coupling said first and second nodes respectively to a charge sharing line in response to an additional precharge signal at their common coupled gates thereof, wherein said additional precharge signal is activatable prior to said precharge signal and said complement of said precharge signal.
2. The integrated circuit device of claim 1 wherein said first pair of cross-coupled transistors are P-channel devices and said second pair of cross-coupled transistors are N-channel devices.
3. The integrated circuit device of claim 1 wherein said first pair of common gate coupled transistors are N-channel devices and said second pair of common gate coupled transistors are P-channel devices.
4. The integrated circuit device of claim 1 wherein said first and second additional transistors are N-channel devices.
5. The integrated circuit device of claim 1 wherein charge is shared between said pairs of first and second complementary bit lines as said integrated circuit device enters a precharge portion of a memory circuit cycle.
6. The integrated circuit device of claim 1 comprising a multi-chip package device.