US 11,774,999 B2
Voltage reference generation with compensation for temperature variation
Yuan Gao, Cugnaux (FR); Simon Brule, Toulouse (FR); and Estelle Huynh, Villeneuve-Tolosane (FR)
Assigned to NXP USA, Inc., Austin, TX (US)
Filed by NXP USA, INC., Austin, TX (US)
Filed on Sep. 30, 2020, as Appl. No. 17/38,773.
Claims priority of application No. 19306379 (EP), filed on Oct. 24, 2019.
Prior Publication US 2021/0124386 A1, Apr. 29, 2021
Int. Cl. G05F 3/26 (2006.01)
CPC G05F 3/262 (2013.01) 12 Claims
OG exemplary drawing
 
1. An apparatus comprising:
a Zener diode circuit, coupled between a first supply terminal and a second supply terminal, to provide a first input reference voltage level;
a voltage reduction circuit, arranged in parallel with the Zener diode circuit, to provide a second input reference voltage level that tracks the first input reference voltage level; and
a proportional-to-absolute temperature (PTAT) circuit includes a differential circuit having first and second differential paths to provide an output drive current and an output reference voltage at an output node of the PTAT circuit, having a feedforward path to the output node based on the second input reference voltage level, wherein:
the first differential path includes a first transistor circuit to pass current between the first supply terminal and the second supply terminal, the first transistor circuit having a control terminal driven in response to the second input reference voltage level,
the second differential path includes a second transistor circuit to pass current between the first supply terminal and the second supply terminal, the second transistor circuit having a control terminal driven in response to the output reference voltage at the output node, and
the PTAT circuit is configured to provide a level of temperature compensation that is set by a ratio of current density of the first transistor circuit and the second transistor circuit.