| 摘要 |
A Dynamic Random Access Memory (DRAM) device includes a bus for distributing a boosted voltage VCCP within the device. A conventional internal voltage regulator, ring oscillator, and charge pump help to boost the boosted voltage VCCP on the bus when the voltage VCCP falls below a preset minimum. During testing of the DRAM device, when the demand on the boosted voltage VCCP can be four or more times as much as it is under normal operating conditions, an external current source drives current ICCP into an unused bond pad, such as a no-connection (NC) or address signal bond pad. An NMOS transistor switch then connects this bond pad to the boosted voltage VCCP bus when a pump circuit controlled by the ring oscillator activates the switch. As a result, the external current augments the efforts of the internal charge pump to boost the voltage VCCP during testing, so there is no need to build the internal charge pump with oversized capacitors to handle the excessive VCCP demand during testing.
|
