diff --git a/src/stm32/Kconfig b/src/stm32/Kconfig
index aa67dc91e..65e7e36d0 100644
--- a/src/stm32/Kconfig
+++ b/src/stm32/Kconfig
@@ -208,7 +208,8 @@ config CLOCK_FREQ
     default 64000000 if MACH_STM32G0
     default 150000000 if MACH_STM32G431
     default 170000000 if MACH_STM32G474
-    default 400000000 if MACH_STM32H7 # 400Mhz is max Klipper currently supports
+    default 520000000 if MACH_STM32H723
+    default 400000000 if MACH_STM32H743 || MACH_STM32H750
     default 80000000 if MACH_STM32L412
     default 64000000 if MACH_N32G45x && STM32_CLOCK_REF_INTERNAL
     default 128000000 if MACH_N32G45x
diff --git a/src/stm32/stm32h7_adc.c b/src/stm32/stm32h7_adc.c
index a630f2668..0d7d00f9d 100644
--- a/src/stm32/stm32h7_adc.c
+++ b/src/stm32/stm32h7_adc.c
@@ -161,7 +161,8 @@ static const uint8_t adc_pins[] = {
 #define ADC_ATICKS 0b110
 #define ADC_ATICKS_H723_ADC3 0b111
 // 400Mhz stm32h7: clock=25Mhz, Tsamp=387.5, Tconv=394, total=15.76us
-// 400Mhz stm32h723 adc3: clock=50Mhz, Tsamp=640.5, Tconv=653, total=13.06us
+// 520Mhz stm32h723: clock=32.5Mhz, Tsamp=387.5, Tconv=394, total=12.12us
+// 520Mhz stm32h723 adc3: clock=65Mhz, Tsamp=640.5, Tconv=653, total=10.05us
 // 80Mhz stm32l4: clock=20Mhz, Tsamp=247.5, Tconv=260, total=13.0us
 // 150Mhz stm32g4: clock=37.5Mhz, Tsamp=247.5, Tconv=260, total=6.933us