Apparatus and method of generating power up signal of semiconductor integrated circuit
View Patent ↗An apparatus for generating a power up signal for a semiconductor memory chip includes a temperature information providing unit that outputs a control voltage corresponding to predetermined temperature information. A power up signal generating unit generates the power up signal based at least on one of an external voltage or the control voltage.
1. An apparatus for generating a power up signal for a semiconductor integrated circuit, the apparatus comprising:
a temperature information providing unit that outputs a control voltage corresponding to a predetermined temperature information; and
a power up signal generating unit that generates the power up signal based on a level of a power supply voltage, and changes a level of the power up signal according to the control voltages, wherein the power up signal generating unit includes:
a voltage level converting unit that converts the power supply voltage to a voltage level obtained by multiplying the power supply voltage by a predetermined ratio;
a detecting unit that detects whether the voltage level of the voltage level converting unit is equal to or more than a set level to generate the power up signal according to a detected result; and
a correcting unit that corrects a level of the power up signal according to the control voltage.
2. The apparatus of claim 1 , wherein the temperature information providing unit includes:
a temperature information output unit that outputs a current temperature information indicative of a temperature outside of the semiconductor integrated circuit; and
a digital-to-analog converting unit that converts the temperature information into the control voltage.
3. The apparatus of claim 2 , wherein the digital-to-analog converting unit includes:
a plurality of transistors having drains, sources connected to a power terminal and gates receiving the temperature information;
a plurality of first resistors having first ends correspondingly connected to the drains of the plurality of transistors and second ends; and
a second resistor having a first end commonly connected to the second ends of the plurality of first resistors, and a second end connected to a ground terminal.
4. The apparatus of claim 3 , wherein the control voltage is output from a connection node between the first resistors and the second resistor.
5. The apparatus of claim 1 , wherein the correcting unit includes:
a transistor that has a source connected to a power terminal, a gate receiving the control voltage as an input, and a drain connected to a power up signal output path of the detecting unit.
6. The apparatus of claim 1 , wherein the voltage level converting unit includes:
a plurality of resistors connected between a power terminal and a ground terminal.
7. The apparatus of claim 1 , wherein the detecting unit includes:
a first transistor having a drain, a source connected to a power terminal and a gate connected to a ground terminal;
a second transistor having a drain connected to the drain of the first transistor, a source connected to the ground terminal, and a gate receiving an output of the voltage level converting unit; and
an inverter having an input terminal connected to the drain of the second transistor.
8. The apparatus of claim 1 , wherein the temperature information has at least two bits.