To achieve the standby current mentioned in the device datasheet ((Document Number: 001-54459 Rev. *G)), the following needs to be ensured:
1. None of the GPIOs is sourcing any current.
2. I2C_ON bit in the SLP_CFG2 and the USB_enable bit in USB_CR0 register is disabled.
3. The buzz rate is set to to 1/32768 using the ALT_Buzz bits of the SLP_CFG2 register.
4. The current is measured by putting the ammeter between supply and Vdd of pin i.e. the current measurement should not include any current other than device current.
Attached a code example that achieves the Isb1 current on the CY3280-20xx6A development kit.