diff --git a/Software/VNA_embedded/Application/Drivers/FPGA/FPGA.cpp b/Software/VNA_embedded/Application/Drivers/FPGA/FPGA.cpp
index e600c59..7f54ed6 100644
--- a/Software/VNA_embedded/Application/Drivers/FPGA/FPGA.cpp
+++ b/Software/VNA_embedded/Application/Drivers/FPGA/FPGA.cpp
@@ -331,15 +331,19 @@ void HAL_SPI_TxRxCpltCallback(SPI_HandleTypeDef *hspi) {
 }
 }
 
-void FPGA::StartSweep() {
+void FPGA::StopSweep() {
 	Low(AUX3);
+}
+
+void FPGA::StartSweep() {
+	StopSweep();
 	Delay::us(1);
 	High(AUX3);
 }
 
 void FPGA::AbortSweep() {
 	// abort any FPGA operation by pulling sweep pin low
-	Low(AUX3);
+	StopSweep();
 	// data transfer of a datapoint might still be active, abort
 	HAL_SPI_DMAStop(&FPGA_SPI);
 	busy_reading = false;
diff --git a/Software/VNA_embedded/Application/Drivers/FPGA/FPGA.hpp b/Software/VNA_embedded/Application/Drivers/FPGA/FPGA.hpp
index dff1af1..25a34b4 100644
--- a/Software/VNA_embedded/Application/Drivers/FPGA/FPGA.hpp
+++ b/Software/VNA_embedded/Application/Drivers/FPGA/FPGA.hpp
@@ -135,6 +135,7 @@ uint16_t GetStatus();
 void OverwriteHardware(uint8_t attenuation, LowpassFilter filter, bool lowband, bool port1_enabled, bool port2_enabled);
 void DisableHardwareOverwrite();
 
+void StopSweep();
 void StartSweep();
 void AbortSweep();
 
diff --git a/Software/VNA_embedded/Application/VNA.cpp b/Software/VNA_embedded/Application/VNA.cpp
index de540b0..c270852 100644
--- a/Software/VNA_embedded/Application/VNA.cpp
+++ b/Software/VNA_embedded/Application/VNA.cpp
@@ -411,6 +411,10 @@ void VNA::Work() {
 	if(Trigger::GetMode() != Trigger::Mode::ExtRef) {
 		HW::Ref::update();
 	}
+	// Stop the sweep. The source may not have been active for the last phase but the PLL
+	// must be enabled for reading the temperature. Stopping the sweep implicitly enables
+	// the source PLL
+	FPGA::StopSweep();
 	// Compile info packet
 	Protocol::PacketInfo packet;
 	packet.type = Protocol::PacketType::DeviceStatus;