diff --git a/src/laser_diode/max5719.rs b/src/laser_diode/max5719.rs
index dd50684..c43e419 100644
--- a/src/laser_diode/max5719.rs
+++ b/src/laser_diode/max5719.rs
@@ -9,7 +9,8 @@ pub const SPI_MODE: spi::Mode = spi::Mode {
     polarity: spi::Polarity::IdleLow,
     phase: spi::Phase::CaptureOnFirstTransition,
 };
-pub const SPI_CLOCK_MHZ: MegahertzU32 = MegahertzU32::from_raw(10);
+// MAX5719 Max Frequency: 50MHz | SPI2 Max Frequency: 21MHz
+pub const SPI_CLOCK_MHZ: MegahertzU32 = MegahertzU32::from_raw(21);
 
 pub const MAX_VALUE: u32 = 0xFFFFF;
 
diff --git a/src/thermostat/ad5680.rs b/src/thermostat/ad5680.rs
index bc09518..cf8862c 100644
--- a/src/thermostat/ad5680.rs
+++ b/src/thermostat/ad5680.rs
@@ -10,7 +10,8 @@ pub const SPI_MODE: spi::Mode = spi::Mode {
     polarity: spi::Polarity::IdleLow,
     phase: spi::Phase::CaptureOnSecondTransition,
 };
-pub const SPI_CLOCK_MHZ: MegahertzU32 = MegahertzU32::from_raw(30);
+// MAX Clock Frequency: 30MHz | SPI1 Max Frequency 42MHz
+pub const SPI_CLOCK_MHZ: MegahertzU32 = MegahertzU32::from_raw(21);
 
 pub const MAX_VALUE: u32 = 0x3FFFF;
 
diff --git a/src/thermostat/ad7172/mod.rs b/src/thermostat/ad7172/mod.rs
index 1578e20..f12e608 100644
--- a/src/thermostat/ad7172/mod.rs
+++ b/src/thermostat/ad7172/mod.rs
@@ -15,8 +15,8 @@ pub const SPI_MODE: spi::Mode = spi::Mode {
     polarity: spi::Polarity::IdleHigh,
     phase: spi::Phase::CaptureOnSecondTransition,
 };
-/// 2 MHz
-pub const SPI_CLOCK_MHZ: MegahertzU32 = MegahertzU32::from_raw(2);
+/// AD7172 Max Frequency: 40MHz | SPI3 Max Frequency: 21MHz
+pub const SPI_CLOCK_MHZ: MegahertzU32 = MegahertzU32::from_raw(21);
 
 pub const MAX_VALUE: u32 = 0xFF_FFFF;