US 11,942,866 B2
Transconductance amplifier for buck-boost converter
Rajesh Karri, Visakhapatnam (IN); and Arun Khamesra, Bangalore (IN)
Assigned to Cypress Semiconductor Corporation, San Jose, CA (US)
Filed by Cypress Semiconductor Corporation, San Jose, CA (US)
Filed on Jul. 21, 2021, as Appl. No. 17/381,679.
Claims priority of provisional application 63/074,060, filed on Sep. 3, 2020.
Prior Publication US 2022/0069711 A1, Mar. 3, 2022
Int. Cl. H03F 1/02 (2006.01); G06F 13/42 (2006.01); H02M 3/158 (2006.01); H03F 1/30 (2006.01)
CPC H02M 3/1582 (2013.01) [G06F 13/4282 (2013.01); H03F 1/0227 (2013.01); H03F 1/301 (2013.01); H03F 2200/351 (2013.01); H03F 2200/462 (2013.01)] 20 Claims
OG exemplary drawing
 
1. An error amplifier comprising:
an output pin coupled to a pulse width modulation (PWM) comparator of a buck-boost converter;
a first transconductance amplifier to adjust an output current at the output pin, wherein the first transconductance amplifier operates in a constant voltage mode and comprises:
a first positive input to receive a first voltage reference; and
a first negative input coupled to a tap point of a voltage divider coupled between a voltage bus and a ground of the buck-boost converter;
a second transconductance amplifier to also adjust the output current at the output pin, wherein the second transconductance amplifier operates in a constant current mode and comprises:
a second positive input to receive a second voltage reference; and
a second negative input coupled to a current sense amplifier, the current sense amplifier being coupled to a sense resistor positioned inline along the voltage bus.